Patent application title: MICROBIOLOGICAL PRODUCTION OF 3-HYDROXYISOBUTYRIC ACID
Inventors:
Achim Marx (Gelnhausen, DE)
Achim Marx (Gelnhausen, DE)
Markus Poetter (Muenster, DE)
Markus Poetter (Muenster, DE)
Stefan Buchholz (Hanau, DE)
Stefan Buchholz (Hanau, DE)
Alexander May (Darmstadt, DE)
Hermann Siegert (Seeheim-Jugenheim, DE)
Georg Fuchs (Heitersheim, DE)
Birgit Alber (Stuttgart, DE)
Lothar Eggeling (Juelich, DE)
Assignees:
Evonik Roehm GmbH
IPC8 Class: AC12P742FI
USPC Class:
Class name:
Publication date: 2015-08-06
Patent application number: 20150218601
Abstract:
The present invention relates to a cell which has been modified in
comparison with its wild type in such a way that it is capable of forming
more, by comparison with its wild, 3-hydroxyisobutyric acid or
polyhydroxyalkanoates based on 3-hydroxyisobutyric acid via
methylmalonate-semialdehyde or 3-hydroxybutyryl-coenzyme A as precursors.
The invention also relates to a method of generating a genetically
modified cell, to the genetically modified cell obtainable by these
methods, to a method of producing 3-hydroxyisobutyric acid or
polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, to a method of
producing methacrylic acid or methacrylic esters, and to a method of
producing polymethacrylic acid or polymethacrylic esters. The present
invention furthermore relates to an isolated DNA, to a vector, to the use
of this vector for transforming a cell, to a transformed cell, and to a
polypeptide.Claims:
1. A cell which has been genetically modified in comparison with its wild
type in such a way that it is capable of forming more 3-hydroxyisobutyric
acid from L-valine, as a carbon source, in comparison with its wild type,
wherein more 3-hydroxyisobutyric acid is formed from
3-hydroxyisobutyryl-coenzyme A as a precursor, wherein activities of
enzymes E8, E60, E61, E79, and E80 are increased
in the cell compared to its wild type, wherein: E8 is a
3-hydroxyisobutyryl-coenzyme A hydrolase EC 3.1.2.4, E60 is an
enoyl-coenzyme A hydratase EC 4.2.1.17, E61 is a
2-methylacyl-coenzyme A dehydrogenase EC 1.3.99.12 E79 is a
2-oxoisovalerate dehydrogenase EC 1.2.4.4, and E80 is an amino acid
transferase EC 2.6.1.42, wherein the cell is an Escherichia coli cell.
2. A method of preparing a genetically modified cell which is capable of forming 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid using 3-hydroxybutyryl-coenzyme A, as a precursors, the method comprising increasing, in the cell, the activity of the enzymes of claim 1, wherein the cell is an Escherichia coli cell.
3. A genetically modified cell obtainable by the method of claim 2.
4. A method of producing 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, the method comprising bringing a cell of claim 1 into contact with a nutrient medium comprising L-valine, as a carbon source, under conditions under which 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid are formed from the carbon source, and, optionally, purifying the 3-hydroxyisobutyric acid from the nutrient medium.
5. A method of preparing methacrylic acid or methacrylic ester, the method comprising: IA) preparing 3-hydroxyisobutyric acid by the method of claim 4 and, optionally, neutralizing the 3-hydroxyisobutyric acid, and IB) dehydrating the 3-hydroxyisobutyric acid with formation of methacrylic acid and, optionally, esterifying the methacrylic acid.
6. A method of preparing methacrylic acid or methacrylic esters, the method comprising: IIA) preparing a polyhydroxyalkanoate based on 3-hydroxybutyric acid by the method of claim 4, IIB) cleaving the polyhydroxyalkanoates with formation of 3-hydroxyisobutyric acid and, optionally, neutralizing the 3-hydroxyisobutyric acid, and IIC) dehydrating the 3-hydroxyisobutyric acid with formation of methacrylic acid and, optionally, esterifying the methacrylic acid.
7. A method of preparing polymethacrylic acid or polymethacrylic esters, the method comprising: IIIA) preparing methacrylic acid by the method as claimed in claim 5, and IIIB) free-radical polymerizing the methacrylic acid.
8. A method of preparing polymethacrylic acid or polymethacrylic esters, the method comprising: IIIA) preparing methacrylic acid by the method as claimed in claim 6, and IIIB) free-radical polymerizing the methacrylic acid.
Description:
[0001] This application is a Divisional of U.S. application Ser. No.
12/303,161, filed Apr. 6, 2009, which is the U.S. National Stage of
International Application No. PCT/EP2007/0055394, filed Jun. 1, 2007,
which claimed priority to German application no. 102006025821.5, filed
Jun. 2, 2006, of which all of the disclosures are incorporated herein by
reference in their entireties.
[0002] The present invention relates to cells which have been genetically modified in comparison with their wild type, to methods of generating a genetically modified cell, to the genetically modified cells obtainable by these methods, to a process for the preparation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, to a process for the preparation of methacrylic acid or methacrylic esters, and to a process for the preparation of polymethacrylic acid or polymethacrylic esters. The present invention furthermore relates to an isolated DNA, to a vector, to the use of this vector for the transformation of a cell, to a transformed cell, and to a polypeptide.
[0003] Methacrylic acid is an important intermediate which is employed for the preparation of polymers, in particular in the form of its alkyl esters. An example of a well-known methacrylic acid derivative is the methyl ester of methacrylic acid. The current global annual production of methyl methacrylate amounts to approximately 1.5 million tonnes. The polymethacrylic esters are raw materials in the plastics sector with a multiplicity of uses.
[0004] Methacrylic acid is usually produced commercially by means of the heterogeneous gas-phase oxidation of C4-carbon compounds such as butylene, isobutylene, butane, isobutane, t-butyl alcohol or methacrolein by two-step catalysis on solid multi-metal oxide compositions as the catalyst. The resulting product gas mixture, which, besides methacrylic acid, also comprises a large number of secondary products, is subsequently either subjected to a total condensation reaction, generating aqueous methacrylic acid solution, or absorbed in a suitable solvent mixture. This is usually followed by further purification of the resulting liquid phases by means of distillation, crystallization, extraction, or a combination of these measures. Besides the catalytic gas-phase oxidation of C4-carbon compounds, methacrylic acid can also be formed from isobutyric acid by catalytic oxidative dehydrogenation, as is described for example in EP-A-0 356 315. A further possibility for preparing methacrylic acid is what is known as the "ACH process", in which acetone cyanohydrin and sulfuric acid are reacted with the formation of methacrylamide as intermediate, which then reacts further with water to give methacrylic acid. The resulting methacrylic acid is subsequently purified by distillation. This process is described for example in EP-A-1 359 137.
[0005] The disadvantage of these conventional processes for the preparation of methacrylic acid is, inter alia, that during both the preparation of the methacrylic acid itself and during the subsequent steps, which involve purification by distillation, the process steps, which cause thermal stress, result, owing to the pronounced susceptibility of methacrylic acid to polymerization, in the formation of dimers or oligomers; this not only entails additional purification efforts, but also yield losses.
[0006] It was an object of the present invention to overcome the disadvantages of the prior art.
[0007] In particular, it was an object of the present invention to provide a process for the preparation of methacrylic acid which generates methacrylic acid with a minimum of steps which involve thermal stress.
[0008] Furthermore, it is intended that this process makes possible the preparation of methacrylic acid from renewable resources, in particular from carbohydrates and/or glycerol.
BRIEF DESCRIPTIONS OF THE SEVERAL VIEWS OF DRAWINGS
[0009] FIG. 1 shows the conversion of succinyl-coenzyme A into methylmalonyl-coenzyme A with catalysis by the enzyme E1.
[0010] FIG. 2 shows the conversion of methylmalonyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E2 to E4 in accordance with the first alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0011] FIG. 3 shows the conversion of (R)-methylmalonyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E4, E6 and E7 in accordance with the second alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3 hydroxyisobutyric acid.
[0012] FIG. 4 shows the conversion of methylmalonyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E4, E5 and E7 in accordance with the third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0013] FIG. 5 shows the conversion of 3-hydroxyisobutyric acid into a polyhydroxyalkanoate with catalysis by the enzymes E8 and E9.
[0014] FIG. 6 shows the conversion of phosphoenolpyruvate or pyruvate into oxalacetate with catalysis by the enzymes E10 or E11 according to a special embodiment of the first, second or third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0015] FIG. 7 shows the conversion of oxalacetate into succinyl-coenzyme A with catalysis by the enzymes E12 to E15 according to a first special embodiment of the first, second or third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0016] FIG. 8 shows the conversion of oxalacetate into succinyl-coenzyme A with catalysis by the enzymes E13 to E16 and E24 to E26 according to a second special embodiment of the first, second or third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0017] FIG. 9 shows the conversion of oxalacetate into succinyl-coenzyme A with catalysis by the enzymes E16, E24, E27 and E28 according to a third special embodiment of the first, second or third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0018] FIG. 10 shows the conversion of L-glutamate into succinyl-coenzyme A with catalysis by the enzymes E46 and E28 in accordance with a further special embodiment of the first, second or third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0019] FIG. 11 shows the conversion of acetyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E4, E5 and E47 to E52 in accordance with a first alternative of the second special embodiment of the cell according to the invention, where propionyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0020] FIG. 12 shows the conversion of propionyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E2 to E4, E6, E7 and E47 to E52 in accordance with a second alternative of the second special embodiment of the cell according to the invention, where propionyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0021] FIG. 13 shows the conversion of propionyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E2 to E4, E7 and E47 to E52 in accordance with a third alternative of the second special embodiment of the cell according to the invention, where propionyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0022] FIG. 14 shows the conversion of propionyl-coenzyme A into 3-hydroxyisobutyric acid with catalysis by the enzymes E2 to E4, E7 and E47 to E52 in accordance with a fourth, fifth alternative of the second special embodiment of the cell according to the invention, where propionyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0023] FIG. 15 shows the conversion of β-alanine into 3-hydroxyisobutyric acid with catalysis by the enzymes E10 to E12, E56, E72 and E73 according to a third special embodiment of the cell according to the invention, where acrylyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0024] FIG. 16 shows the conversion of pyruvate into 3-hydroxyisobuytric acid with catalysis by the enzymes E75 to E79, E60, E61 and E8 according to a first alternative of the first special embodiment of the second variant of the cell according to the invention, where isobutyryl-coenzyme A is formed as intermediate and 3-hydroxyisobutyryl-coenzyme A as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0025] FIG. 17 shows the conversion of L-valine into 3-hydroxyisobutyric acid with catalysis by the enzymes E8, E60, E61, E79 and E80 according to a second alternative of the first special embodiment of the second variant of the cell according to the invention, where isobutyryl-coenzyme A is formed as intermediate and 3-hydroxyisobutyryl-coenzyme A as precursor in the production of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid.
[0026] FIG. 18 shows the conversion of beta-Alanine to 3 hydroxyisobutyric acid.
[0027] FIG. 19 shows the conversion of (S)-2-Acetolactate to methylacrylyl-coenzyme A.
[0028] FIG. 20 shows the conversion of L-valine to 3 hydroxyisobutyric acid.
[0029] A contribution to achieving the abovementioned aims is provided by a cell which has been genetically modified in comparison with its wild type in such a way that it is capable of forming more 3-hydroxyisobutyric acid, or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, but preferably more 3-hydroxyisobutyric acid, in comparison with its wild type, this formation preferably taking place via methylmalonate semialdehyde or via 3-hydroxyisobutyryl-coenzyme A as precursor.
[0030] In the event that the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via methylmalonate semialdehyde as precursor, it is furthermore preferred that the formation takes place via succinyl-coenzyme A, propionyl-coenzyme A or acryloyl-coenzyme A, especially preferably via succinyl-coenzyme A, as further intermediate. In the event that the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor, it is furthermore preferred that the formation takes place via isobutyryl-coenzyme A or via 3-hydroxybutyryl-coenzyme A, preferably via 3-hydroxybutyryl-coenzyme A, as further intermediate.
[0031] The term "precursor" as used in the present context defines a chemical compound which can be converted enzymatically into 3-hydroxyisobutyric acid in just one reaction step, while the term "intermediate" defines a chemical compound which cannot be converted enzymatically into 3-hydroxyisobutyric acid in just one reaction step.
[0032] The term "3-hydroxyisobutyric acid" as used in the present context always describes the corresponding C4-carboxylic acid in the form in which it is present as a function of the pH, after having been formed by the microorganisms in question. As a consequence, the term always comprises the pure acid form (3-hydroxyisobutyric acid), the pure base form (3-hydroxyisobutyrate) and mixtures of protonated and deprotonated forms of the acid. Furthermore, the term "3-hydroxyisobutyric acid" comprises, in principle, both the (R) and the (S) stereoisomer, the (S) stereoisomer being especially preferred.
[0033] The wording "that it is capable of forming more 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid in comparison with its wild type" also applies in the event that the wild type of the genetically modified cell is not capable of forming any 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, but at least no detectable amounts of these compounds, and that detectable amounts of these components are only capable of being formed after the genetic modification.
[0034] A "wild type" of a cell preferably refers to a cell whose genome is present in a state as generated naturally as the result of evolution. The term is used both for the entire cell and for individual genes. As a consequence, the term "wild type" does not cover in particular those cells, or those genes, whose gene sequences have at least in part been modified by man by means of recombinant methods.
[0035] The 3-hydroxyisobutyric acid can subsequently give rise to methacrylic acid by subjecting it to a dehydration reaction under mild conditions. In the case of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, the vesicles present in the cells, which are filled with these polyhydroxyalkanoates, can be isolated and the polymers can subsequently be cleaved to give 3-hydroxyisobutyric acid, which can then be dehydrated to give methacrylic acid.
[0036] In this context, it is preferred according to the invention that the genetically modified cell has been genetically modified in such a way that it forms at least twice, especially preferably at least 10 times, more preferably at least 100 times, even more preferably at least 1000 times and most preferably at least 10 000 times more 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid than the wild type of the cell within a defined time interval, preferably within 2 hours, even more preferably within 8 hours and most preferably within 24 hours. The increase in the formation of product can be determined in this context for example by growing the cell according to the invention and the wild-type cell in each case separately, but under identical conditions (identical cell density, identical nutrient medium, identical culture conditions) for a particular time interval in a suitable nutrient medium and subsequently determining the amount of target product (3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid) in the nutrient medium.
[0037] The cells according to the invention may be prokaryotic or eukaryotic cells. They may take the form of mammalian cells (such as, for example, human cells), of plant cells or of microorganisms such as yeasts, fungi or bacteria, with microorganisms being especially preferred and bacteria and yeasts being most preferred.
[0038] Suitable bacteria, yeasts or fungi are in particular those bacteria, yeasts or fungi which have been deposited at the Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH (DSMZ), Brunswick, Germany, as bacterial, yeast or fungal strains. Bacteria which are suitable according to the invention belong to the genera detailed under
http://www.dsmz.de/species/bacteria.htm, yeasts which are suitable according to the invention belong to those genera which are detailed under http://www.dsmz.de/species/yeasts.htm, and fungi which are suitable according to the invention are those which are detailed under http://www.dsmz.de/species/fungi.htm.
[0039] Cells which are especially preferred according to the invention are those of the genera Corynebacterium, Brevibacterium, Bacillus, Acinetobacter, Lactobacillus, Lactococcus, Candida, Pichia, Kluveromyces, Saccharomyces, Escherichia, Zymomonas, Yarrowia, Methylobacterium, Ralstonia, Pseudomonas, Burkholderia and Clostridium, with Brevibacterium flavum, Brevibacterium lactofermentum, Escherichia coli, Saccharomyces cerevisiae, Kluveromyces lactis, Candida blankii, Candida rugosa, Corynebacterium glutamicum, Corynebacterium efficiens, Zymonomas mobilis, Yarrowia lipolytica, Methylobacterium extroquens, Ralstonia eutropha, especially Ralstonia eutropha H16, Rhodospirillum rubrum, Rhodobacter sphaeroides, Para coccus versutus, Pseudomonas aeroginosa, Acinetobacter calcoaceticus and Pichia pastoris being especially preferred.
[0040] In accordance with a first variant of the cell according to the invention, the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via methylmalonate semialdehyde as precursor.
[0041] In accordance with a first special embodiment of this first variant of the cell according to the invention, it is preferred that the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoate based on 3-hydroxyisobutyric acid preferentially takes place via succinyl-coenzyme A as intermediate, where the cell preferentially is capable of utilizing carbohydrates, glycerol or glutamate as the carbon source.
[0042] Here, it may be advantageous in the context of the first special embodiment of the first variant of the cell according to the invention that the cell according to the invention features an increased activity of an enzyme E1, which catalyzes the conversion of succinyl-coenzyme A into methylmalonyl-coenzyme A, in comparison with its wild type (see FIG. 1).
[0043] The term "increased activity of an enzyme" as used above in connection with the enzyme E1 and in what follows in the context of the enzymes E2 etc. is preferably to be understood as increased intracellular activity.
[0044] What now follows on increasing the enzymatic activity in cells applies both to increasing the activity of the enzyme E1 and to all enzymes mentioned thereafter, whose activity can, if appropriate, be increased.
[0045] In principle, an increase in the enzymatic activity can be achieved by increasing the copy number of the gene sequence(s) which code for the enzyme, by using a strong promoter or by using a gene or allele which codes for a corresponding enzyme with an increased activity, and, if appropriate, combining these measures. Cells which have been genetically modified in accordance with the invention are generated for example by transformation, transduction, conjugation or a combination of these methods with a vector which comprises the desired gene, an allel of this gene or parts thereof, and a vector which makes possible the expression of the gene. The heterologous expression is achieved in particular by integration of the gene, or of the alleles, into the chromosome of the cell or into an extrachromosomally replicating vector.
[0046] An overview over the possibilities for increasing the enzymatic activity in cells with pyruvate carboxylase by way of example is found in DE-A-100 31 999, which is hereby incorporated by reference and whose disclosure content regarding the possibilities for increasing the enzymatic activity in cells forms part of the disclosure of the present invention.
[0047] The expression of the enzymes or genes mentioned hereinabove and in each case hereinbelow can be detected in the gel with the aid of 1- and 2-dimensional protein gel separation and subsequent visual identification of the protein concentration using suitable evaluation software. When the increase in an enzymatic activity is based exclusively on an increase in the expression of the gene in question, the quantification of the increase in the enzymatic activity can be determined in a simple manner by comparing the 1- or 2-dimensional protein separations between the wild type and the genetically modified cell. A conventional method of preparing the protein gels in coryneform bacteria, and of identifying the proteins, is the procedure described by Hermann et al. (Electrophoresis, 22: 1712.23 (2001)). The protein concentration can also be analyzed by Western blot hybridization using an antibody which is specific for the protein to be detected (Sambrook et al., Molecular Cloning: a laboratory manual, 2nd Ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. USA, 1989) followed by visual evaluation with suitable software for determining the concentration (Lohaus and Meyer (1989) Biospektrum, 5: 32-39; Lottspeich (1999), Angewandte Chemie 111: 2630-2647). The activity of DNA-binding proteins can be measured by means of DNA band shift assays (also referred to as gel retardation) (Wilson et al. (2001) Journal of Bacteriology, 183: 2151-2155). The effect of DNA-binding proteins on the expression of other genes can be detected by various, extensively described methods of the reporter gene assay (Sambrook et al., Molecular Cloning: a laboratory manual, 2nd Ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. USA, 1989). The intracellular enzymatic activities can be detected by various methods which have been described (Donahue et al. (2000) Journal of Bacteriology 182 (19): 5624-5627; Ray et al. (2000) Journal of Bacteriology 182 (8): 2277-2284; Freedberg et al. (1973) Journal of Bacteriology 115 (3): 816-823). In the event that no specific methods for determining the activity of a particular enzyme are detailed in what follows, the determination of the increase in the enzymatic activity, and also the determination of the reduction in an enzymatic activity, is preferably carried out by means of the methods described in Hermann et al., Electrophoresis, 22: 1712-23 (2001), Lohaus et al., Biospektrum 5 32-39 (1998), Lottspeich, Angewandte Chemie 111: 2630-2647 (1999) and Wilson et al. (2001) Journal of Bacteriology, 183: 2151-2155 (2001).
[0048] If increasing the enzymatic activity is brought about by mutating the endogenous gene, such mutations can be generated either undirected, using traditional methods such as for example by UV irradiation or by mutagenic chemicals, or directed by means of recombinant methods such as deletion(s), insertion(s) and/or nucleotide substitution(s). These mutations give rise to genetically modified cells. Especially preferred mutants of enzymes are in particular also those enzymes which are no longer capable of being feedback-inhibited, or which are at least less capable of being feedback-inhibited, in comparison with the wild-type enzyme.
[0049] If increasing the enzymatic activity is brought about by increasing the expression of an enzyme, then, for example, the copy number of the respective genes are increased, or the promoter and regulatory regions or the ribosomal binding site, which is located upstream of the structural gene, are mutated. Expression cassettes which are incorporated upstream of the structural gene act in the same manner. By means of inducible promoters it is additionally possible to increase the expression at any desired point in time. Furthermore, the enzyme gene may also have assigned to it what are known as enhancer sequences as regulatory sequences; these also bring about an increased gene expression via an improved interaction between RNA polymerase and DNA. Measures for extending the life of the mRNA also improves expression. Furthermore, preventing the degradation of the enzyme protein also enhances the enzymatic activity. Here, the genes or gene constructs are either present in plasmids in different copy numbers, or else they are integrated and amplified in the chromosome. As an alternative, overexpression of the genes in question may also be achieved by modifying the media composition and the control of the culture.
[0050] Instructions for doing so can be found by the skilled worker in Martin et al. (Bio/Technology 5, 137-146 (1987)) in Guerrero et al. (Gene 138, 35-41 (1994)), Tsuchiya and Morinaga (Bio/Technology 6, 428-430 (1988)), in Eikmanns et al. (Gene 102, 93-98 (1991)), in EP-A-0 472 869, in U.S. Pat. No. 4,601,893, in Schwarzer and Puhler ((Bio/Technology 9, 84-87 (1991), in Reinscheid et al. (Applied and Environmental Microbiology 60, 126-132 (1994)), in LaBarre et al. (Journal of Bacteriology 175, 1001-1007 (1993)), in WO-A-96/15246, in Malumbres et al. (Gene 134, 15-24 (1993), in JP-A-10-229891, in Jensen and Hammer (Biotechnology and Bioengineering 58, 191-195 (1998)), inter alia, and in known textbooks of genetics and molecular biology. The above-described measures give rise to genetically modified cells, as do the mutations.
[0051] Plasmids, for example episomal plasmids, are employed for increasing the expression of the genes in question. Suitable plasmids are in particular those which are replicated in coryneform bacteria. A large number of known plasmid vectors such as, for example, pZ1 (Menkel et al., Applied and Environmental Microbiology 64: 549-554 (1989)), pEKEx1 (Eikmanns et al., Gene 107: 69-74 (1991)) or pHS2-1 (Sonnen et al., Gene 107: 69-74 (1991)) are based on the cryptic plasmids pHM1519, pBL1 or pGA1. Other plasmid vectors such as, for example, those based on pCG4 (U.S. Pat. No. 4,489,160) or pNG2 {Serwold-Davis et al., FEMS Microbiology Letters 66: 119-124 (1990)} or pAG1 (U.S. Pat. No. 5,158,891), may be employed in the same manner.
[0052] Others which are suitable are those plasmid vectors with the aid of which the method of amplifying genes by integration into the chromosome can be applied, as has been described for example by Reinscheid et al. (Applied and Environmental Microbiology 60: 126-132 (1994)) for duplicating or amplifying the hom-thrB operon. In this method, the entire gene is cloned into a plasmid vector which is capable of replication in a host (typically Escherichia coli), but not in Corynebacterium glutamicum. Suitable vectors are, for example, pSUP301 (Simon et al, Bio/Technology 1: 784-791 (1983)), pK18mob or pK19mob (Schafer et al., Gene 145: 69-73 (1994)), pGEM-T (Promega Corporation, Madison, Wis., USA), pCR2.1-TOPO (Shuman, Journal of Biological Chemistry 269: 32678-84 (1994)), pCR®Blunt (Invitrogen, Groningen, the Netherlands), pEM1 (Schrumpf et al., Journal of Bacteriology 173: 4510-4516)) or pBGS8 (Spratt et al., Gene 41: 337-342 (1986)). The plasmid vector, which contains the gene to be amplified, is subsequently transferred into the desired Corynebacterium glutamicum strain by means of conjugation or transformation. The conjugation method is described for example in Schafer et al., Applied and Environmental Microbiology 60: 756-759 (1994). Transformation methods are described for example in Thierbach et al., Applied Microbiology and Biotechnology 29: 356-362 (1988), Dunican and Shivnan, Bio/Technology 7: 1067-1070 (1989) and Tauch et al., FEMS Microbiology Letters 123: 343-347 (1994). Following homologous recombination by means of a cross-over event, the resulting strain comprises at least two copies of the gene in question.
[0053] The wording "an activity of an enzyme Ex which is increased in comparison with its wild type" used hereinabove and in what follows is preferably always understood as meaning an activity of the respective enzyme Ex which is increased by a factor of at least 2, especially preferably of at least 10, more preferably of at least 100, even more preferably of at least 1000 and most preferably of at least 10 000. Furthermore, the cell according to the invention which features "an activity of an enzyme Ex which is increased in comparison with its wild type", in particular also a cell whose wild type features no, or at least no detectable, activity of this enzyme Ex and which only shows a detectable activity of this enzyme Ex after increasing the enzymatic activity, for example by means of overexpression. In this context, the term "overexpression", or the wording "increase in the expression" used in what follows also comprises the case that a starting cell, for example a wild-type cell, features no, or at least no detectable, expression and detectable expression of the enzyme Ex is only induced by recombinant methods.
[0054] Accordingly, the wording "reduced activity of an enzyme Ex" used hereinbelow is understood as meaning an activity which is preferably reduced by a factor of at least 0.5, especially preferably of at least 0.1, more preferably of at least 0.01, even more preferably of at least 0.001 and most preferably of at least 0.0001. The reduction in the activity of a specific enzyme can be obtained for example by directed mutation, by the addition of competitive or non-competitive inhibitors or by other measures for reducing the expression of a specific enzyme which are known to the skilled worker.
[0055] In the case of the enzyme E1, which catalyzes the conversion of succinyl-coenzyme A into methylmalonyl-coenzyme A, this preferably takes the form of a methylmalonyl-coenzyme A mutase (EC 5.4.99.2). This enzyme is preferably encoded by the gene selected from the group consisting of mut, mutA, mutB, sbm, sbmA, sbmB, sbm5, bhbA, mcmA, mcmA1, mcmA2, mcmB, mcm1, mcm2, mcm3, icmA, meaA1 and meaA2. The nucleotide sequence of these genes can be found for example in the "Kyoto Encyclopedia of Genes and Genomes" (KEGG database), the databases of the National Center for Biotechnology Information (NCBI) of the National Library of Medicine (Bethesda, Md., USA) or from the nucleotide sequence database of the European Molecular Biologies Laboratories (EMBL, Heidelberg, Germany and Cambridge, UK).
[0056] In accordance with an especially preferred embodiment of the first variant of the cell according to the invention, the enzyme E1 takes the form of the methylmalonyl-coenzyme A mutase from Corynebacterium glutamicum ATCC 13032, which is encoded by a gene with the DNA sequence as shown in SEQ ID No 01 and which has the amino acid as shown in SEQ ID No 02.
[0057] Furthermore, it is preferred in accordance with a first alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the preparation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, that the cell, if appropriate in addition to the increased activity of the enzyme E1, features an activity of at least one of the following enzymes E2 to E4 which is increased in comparison with its wild type (see FIG. 2):
[0058] of an enzyme E2, which catalyzes the conversion of methylmalonyl-coenzyme A into methyl malonate;
[0059] of an enzyme E3, which catalyzes the conversion of methyl malonate into methylmalonate semialdehyde;
[0060] of an enzyme E4 which catalyzes the conversion of methylmalonate semialdehyde into 3-hydroxyisobutyric acid.
[0061] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E2, E3, E4, E2E3, E2E4, E3E4, E2E3E4, where E2E3E4 is most preferred. Furthermore, it is possible that an enzyme is also capable of catalyzing at least two of the above-described reaction steps. Thus, for example, it is possible to employ an enzyme which features both the activity of enzyme E2 and that of enzyme E3 (and which therefore catalyzes the conversion of methylmalonyl-coenzyme A directly into methylmalonate semialdehyde) such as, for example, the malonyl coenzyme A reductase from Sulfolobus tokodaii, which is encoded by the DNA sequence with the SEQ ID No 03 and which has the amino acid sequence as shown in SEQ ID No 04, or else an enzyme which features all three enzymatic activities E2, E3 and E4, such as the malonyl coenzyme A reductase from Chloroflexus aurantiacus (Hugler et al., Journal of Bacteriology 184, pages 2404-2410, 2002).
[0062] In this context, it is especially preferred that the enzyme
[0063] E2 is a methylmalonyl-coenzyme A hydrolase (EC 3.1.2.17),
[0064] E3 is an aldehyde dehydrogenase (EC 1.2.1.3) or an aldehyde oxidase (EC 1.2.3.1) and
[0065] E4 is a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) or a 3-hydroxyacyl-coenzyme A dehydrogenase (EC 1.1.1.35).
[0066] The enzyme E2 is preferably encoded by the aox1 gene. The methylmalonyl-coenzyme A hydrolase from rat liver is described for example in Kovachy et al., "Recognition, isolation, and characterization of rat liver D-methylmalonyl coenzyme A hydrolase", J. Biol. Chem. 258 (1983), pages 11415-11421.
[0067] The enzyme E3 is preferably encoded by genes selected from the group consisting of aldh2, aldh3a1, aldh3a2, aldh1b1, aldh9a1, aldh1a1, aldh1a4, aldh1a1, aldh1a2, mgc80785, mgc83352, mgc89020, dmel-CG31075, cg3752, cg9629, alh-9, alh-1, alh-2, f5O8.35, t7O23.15, f15I1.19, tT17F15.130, ald1, ald2, ald4, ald5, ald6, ac1044Wp, adr417wp, msc7, tb06.5F5.780, aldH, puuC, putA, aldA, badH, alkH, pcD, rsp1591, rs01031, exaC, acoD, dhaL, pchA, aldB, dhaS, betB, ywdH, ycbD, aldX, aldY, aldA1, aldA2, aldC, pcd, cg10546, cg12668, cg12796, scg11A.05, sci30A.27c, sce9.27c, sck13.05c, sc5H4.03, thcA, gabD2, alkH, aldH, aldH1, aldA1, aldY2, aldY3, aldY4, aldY5, aldY6, aldY7 and aldhT.
[0068] Suitable genes for the enzyme E4 are selected from the group consisting of hibadh, cg15093, cg15093, cg4747, mwL2.23, t13k14.90, f19b15.150, hibA, ygbJ, mmsB, mmsB, garR, tsar, mmsB-1, mmsB-2, yfjR, ykwC, ywjF, hibD, glxR, SCM1.40c, hibD, ehhand, hadh2, hadhsc, hsd17B4, loc488110, had, mgC81885, hadh2-prov, cg3415, cg7113, ech-1, ech-8, ech-9, ard-1, yfcX, fadB, faoA, fadB2x, hbd-1, hbd-2, hbd-3, hbd-4, hbd-5, hbd-6, hbd-7, hbd-8, hbd-9, hbd-10, fadJ, rs04421, rs02946, rs05766, bbsD, bbsC, fadB1, fadB2, fadB5, hbdA, pimF, fabJ-1, fabJ, scbac19f3.11, sci35.13, scbac8d1.10c, sc5f2a.15, sc6a5.38, fadC2, fadC4, fadC5, fadC6, had and paaH. Further suitable 3-hydroxyisobutyrate dehydrogenases are described for example in Bannerjee et al. (1970), J. Biol. Chem, 245, pages 1828 to 1835, Steele et al. (1992), J. Biol. Chem., 267, pages 13585 to 13592, Harris et al. (1988), J. Biol. Chem., 263, pages 327 to 331, Harris et al., Biochim. Biophys. Acta, 1645 (1), pages 89 to 95, Hawes et al. (2000), Methods Enzymol., 324, pages 218 to 228, Harris et al., J. Biol. Chem., 275 (49), pages 38780 to 38786, Rougraff et al. (1988), J. Biol. Chem., 263(1), pages 327 to 331, Robinson et al., J. Biol. Chem., 225, pages 511 to 521, Hawes et al. (1995), Biochemistry, 34, pages 4231 to 4237, Hasegawa J. (1981), Agric. Biol. Chem., 45, pages 2805 to 2814, Hawes et al. (1996), FEBS Lett., 389, pages 263 to 267, Hawes et al. (1996), Enzymology and Molecular Biology of Carbonyl Metabolism, Plenum Press, New York, pages 395 to 402, Adams et al. (1994), Structure, 2, pages 651 to 668, Zhang et et. (1999), Biochemistry, 38, pages 11231 to 11238, Mirny et al., (1999), J. Mol. Biol., 291, pages 177 to 196 and Lokanath et al. (2005), J Mol Biol. The disclosure of these publications is hereby incorporated by reference and forms part of the disclosure of the present invention.
[0069] The nucleotide sequences of the abovementioned genes and of further genes for the enzymes E2 to E4 can also be found in the KEGG database, the NCBI database or the EMBL database, inter alia.
[0070] In accordance with an especially preferred embodiment of this alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the preparation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, it is preferred that the malonyl coenzyme A reductase from Sulfolobus tokodaii, which is encoded by the DNA sequence with the SEQ ID No and which has the amino acid sequence as shown in SEQ ID No 04, is employed for the conversion of methylmalonyl-coenzyme A into methylmalonate semialdehyde. In accordance with another especially preferred embodiment of this variant, the malonyl coenzyme A reductase from Chloroflexus aurantiacus (Hugler et al., Journal of Bacteriology 184, pages 2404-2410, 2002) is employed for the conversion of methylmalonyl-coenzyme A into 3-hydroxyisobutyric acid.
[0071] Furthermore, it is preferred in the context of this first alternative of the first special embodiment of the cell according to the invention that the cell features an activity of an enzyme E5, which features the conversion of methylmalonate semialdehyde into propionyl-coenzyme A, which is reduced in comparison with its wild type, this enzyme preferably taking the form of a methylmalonate-semialdehyde dehydrogenase (EC 1.2.1.27).
[0072] In accordance with a second alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the preparation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, it is preferred that the cell, if appropriate in addition to the increased activity of the enzyme E1, features an activity of at least one of the following enzymes E4 to E7 which is increased in comparison with its wild type (see FIG. 3):
[0073] of an enzyme E6, which catalyzes the conversion of (R) methylmalonyl-coenzyme A into (S) methyl-malonyl-coenzyme A;
[0074] of an enzyme E7, which catalyzes the conversion of (S) methylmalonyl-coenzyme A into propionyl-coenzyme A;
[0075] of an enzyme E5, which catalyzes the conversion of propionyl-coenzyme A into methylmalonate semialdehyde;
[0076] of an enzyme E4, which catalyzes the conversion of methylmalonate semialdehyde into 3-hydroxyisobutyric acid.
[0077] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E4, E5, E6, E7, E7, E4E5, E4E6, E4E7, E5E6, E5E7, E6E7, E4E5E6, E4E5E7, E4E6E7, E5E6E7 and E4E5E6E7, with E4E5E6E7 being most preferred.
[0078] In this context, it is especially preferred that the enzyme
[0079] E6 is a methylmalonyl-coenzyme A epimerase (EC 5.1.99.1)
[0080] E7 is a methylmalonyl-coenzyme A decarboxylase (EC 4.1.1.41),
[0081] E5 is a methylmalonate-semialdehyde dehydrogenase (EC 1.2.1.27), and
[0082] E4 is a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) or a 3-hydroxyacyl-coenzyme A dehydrogenase (EC 1.1.1.35).
[0083] In this context, preferred enzymes E4 are those which have already been mentioned above in the context of the first variant of the first preferred embodiment of the cell according to the invention.
[0084] The enzyme E6 is preferably encoded by the mcee gene. A suitable methylmalonyl-coenzyme A decarboxylase (enzyme E7) is described, for example, by Benning et al. in Biochemistry, Vol. 39 (2000), pages 4630-4639.
[0085] Suitable genes for the enzyme E5 are preferably selected from the group consisting of aldh6a1, cg17896, t22c12.10, ald6, putA1, mmsA, mmsA-1, mmsA-2, mmsA-3, mmsA-4, msdA, iolA and iolAB.
[0086] Suitable genes for the enzyme E7 are preferably selected from the group consisting of mmdA, bcc, oadB, oadB2, oadB3, SC1C2.16, SC1G7.10, pccB1, accA2, mmdB, mmdC and ppcB.
[0087] The nucleotide sequences of the abovementioned genes for the enzymes E5, E6 and E7 may, inter alia, also be found in the KEGG database.
[0088] In accordance with a third alternative of the cell according to the invention, where succinyl-coenzyme A is formed as intermediate and methylmalonate semialdehyde as precursor in the preparation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, it is preferred that the cell, if appropriate in addition to the increased activity of the enzyme E1, features an activity of at least one of the following enzymes E4, E5 and E7 which is increased in comparison with its wild type (see FIG. 4):
[0089] of an enzyme E7, which catalyzes the conversion of methylmalonyl-coenzyme A into propionyl-coenzyme A;
[0090] of an enzyme E5, which catalyzes the conversion of propionyl-coenzyme A into methylmalonate-semialdehyde;
[0091] of an enzyme E4, which catalyzes the conversion of methylmalonate-semialdehyde into 3-hydroxyisobutyric acid.
[0092] This pathway corresponds essentially to the second variant of the first preferred embodiment of the cell according to the invention, but, as opposed to the second variant, propionyl-CoA is prepared directly from methylmalonyl-coenzyme A. Preferred enzymes and genes for the enzymes E4, E5 and E7 are those genes or enzymes which have already been mentioned above in connection with the second variant.
[0093] Furthermore, it may in accordance with the first special embodiment of the cell according to the invention (and also in accordance with all embodiments which are still to be described hereinbelow) also be preferred that the cell is capable of converting the formed 3-hydroxyisobutyric acid into a polyhydroxyalkanoate. Such polyhydroxydalkanoates are deposited intracellularly by many microorganisms in the form of highly refractive granula. In this context, it is especially preferred that the cell according to the invention features an activity of at least one of, preferably of the two, the following enzymes E9 and E10 which is increased in comparison with its wild type (see FIG. 5):
[0094] of an enzyme E8, which catalyzes the conversion of 3-hydroxyisobutyric acid into 3-hydroxyisobutyryl-coenzyme A;
[0095] of an enzyme E9, which catalyzes the conversion of 3-hydroxyisobutyryl-coenzyme A to a polyhydroxyalkanoate based on 3-hydroxyisobutyric acid.
[0096] In this context, it is especially preferred that the enzyme
[0097] E8 is a 3-hydroxyisobutyryl CoA hydrolase (EC 3.1.2.4) and
[0098] E9 is a polyhydroxyalkanoate synthase.
[0099] As has already been explained above, the first preferred embodiment of the cell according to the invention generates 3-hydroxyisobutyric acid or the polyhydroxyalkanoates based on 3-hydroxyisobutyric acid from succinyl coenzyme A as intermediate and from methylmalonate semialdehyde as precursor. Here, it may make sense in principle to influence not only one or more of the abovementioned enzyme activities E1 to E9, but also those enzyme activities which lead to an increased formation of succinyl-coenzyme A in the cell.
[0100] In the event that, according to the first special embodiment of the first variant of the cell according to the invention, the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place from carbohydrates or glycerol via succinyl-coenzyme A as intermediate and methylmalonate semialdehyde as precursor, it is, according to a special embodiment of the above-described first, second or third alternative of the cell according to the invention, preferred that the cell features an activity of at least one of the, preferably of the two, following enzymes E10 and E11 which is increased in comparison with its wild type (see FIG. 6):
[0101] of an enzyme E10, which catalyzes the conversion of phosphoenolpyruvate into oxaloacetate;
[0102] of an enzyme E11, which catalyzes the conversion of pyruvate into oxaloacetate.
[0103] In this context, it is especially preferred that the enzyme
[0104] E10 is a phosphoenolpyruvate carboxylase (EC 4.1.1.31) and
[0105] E11 is a pyruvate carboxylase (EC 6.4.1.1).
[0106] The enzyme E10 is preferably encoded by the genes selected from the group consisting of f12m16.21, f14n22.13, k15m2.8, ppc, clpA, pepC, capP, cgl1585, pepC, pck ppc and pccA, where the ppc gene is especially preferred. Phosphoenolpyruvate carboxylases which are preferred according to the invention are also described in particular in U.S. Pat. No. 4,757,009, U.S. Pat. No. 4,980,285, U.S. Pat. No. 5,573,945, U.S. Pat. No. 6,872,553 and U.S. Pat. No. 6,599,732. As regards phosphoenolpyruvate carboxylases, the disclosure content of these publications is hereby incorporated by reference and forms part of the disclosure of the present invention.
[0107] The enzyme E11 is preferably encoded by the genes selected from the group consisting of pc, pcx, cg1516, cg1516, pyc-1, pyc-2, aar162Cp, pyr1, accC-2, pycA, pycA2, pca, cgl0689, pyc, pycB, accC, oadA, acc and accC1, where the pyc gene is especially preferred. Pyruvate carboxylases which are preferred according to the invention are also described in particular in U.S. Pat. No. 6,455,284, U.S. Pat. No. 6,171,833, U.S. Pat. No. 6,884,606, U.S. Pat. No. 6,403,351, U.S. Pat. No. 6,852,516 and U.S. Pat. No. 6,861,246. A further pyruvate carboxylase which is especially preferred according to the invention is that mutant which is described in "A novel methodology employing Corynebacterium glutamicum genome information to generate a new L-lysine-producing mutant", Ohnishi J et al., Applied Microbiology and Biotechnology, vol. 58 (2), pages 217-223 (2002).
[0108] The nucleotide sequences of suitable genes of the enzymes E11 and E12 can be found in the KEGG database, the NCBI database or the EMBL database.
[0109] Starting from the oxaloacetate intermediate stage, there are several possibilities for arriving at succinyl-coenzyme A, which can then be converted into 3-hydroxyisobutyric acid via methylmalonyl-coenzyme A by means of the three variants mentioned at the outset.
[0110] A first pathway leads via fumarate as intermediate. In this case it is preferred in accordance with a first special embodiment of the above-described first, second or third alternative of the cell according to the invention, where methylmalonate-semialdehyde is formed as precursor and succinyl-coenzyme A as intermediate, that the cell, if appropriate additionally to an increased activity of the enzyme E10 or E11, features an activity of at least one of the following enzymes E12 to E15 which is increased in comparison with its wild type (see FIG. 7):
[0111] of an enzyme E12, which catalyzes the conversion of oxaloacetate into malate;
[0112] of an enzyme E13, which catalyzes the conversion of malate into fumarate;
[0113] of an enzyme E14, which catalyzes the conversion of fumarate into succinate;
[0114] of an enzyme E15, which catalyzes the conversion of succinate into succinyl-coenzyme A.
[0115] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E12, E13, E14, E15, E12E13, E12E14, E12E15, E13E14, E13E15, E14E15, E12E13E14, E12E13E15, E12E14E15, E13E14E15, E12E13E14E15, with E12E13E14E15 being most preferred.
[0116] In this context, it is especially preferred that the enzyme
[0117] E12 is a malate dehydrogenase (EC 1.1.1.37) or a malate quinone oxidoreductase (1.1.99.16),
[0118] E13 is a fumarate hydratase (EC 4.2.1.2),
[0119] E14 is a succinate dehydrogenase (EC 1.3.99.1 or EC 1.3.5.1) or a succinate quinone oxidoreductase (1.3.5.1), and
[0120] E15 is a succinate coenzyme A ligase (EC 6.2.1.4 or EC 6.2.1.5).
[0121] The enzyme E12 is preferably encoded by genes selected from the group consisting of mdh1, mdh2, mor1, cg10748, cg10749, cg5362, mdh-1, f46e10.10, f19p19.13, f12m16.14, t30120.4, k15m2.16, f1p2.70, f17i14.150, mn112.18, mik19.17, mdh3, ad1164cp, adr152cp, adr252wp, mdhA, mdhC, mdhB, ybiC, mdh, yiaK, ybiC, allD, citH, yjmC, citH, cgl2380, ldh, sqdB, mqo, yojH, mqoA, mqoB, mqo1, mqo2, mqo3, mqo4 and cgl2001, where the mqo gene and the mdh gene are especially preferred.
[0122] The enzyme E13 is preferably encoded by genes selected from the group consisting of fh, fh1, sc4094, sc4095, t30b22.19, k3k7.11, acr013/cp, fum1, fum2, fum3, fum4, fumH, fumA, fumB, fumC, fumC1, fumC2, fum, ttdA, ttdB, fumB-alpha, fumB-beta, citG, citB, fumX, fum-1 and fum-2, where the fum gene is especially preferred.
[0123] The enzyme E14 is preferably encoded by genes selected from the group consisting of sdh1, sdh2, sdh3, sdh4, sdh5, sdh6, osm1, osm2, sdhA, sdhB, sdhC, sdhD, frdA, frdB, frdC, frdD, ifcA-1, ifcA-2, sdhB-1, sdhB-2, frdC2, cgl0370, cgl0371, cgl0372, scm10.10c, scm10.11c, scm10.12c, sc5g8.25c, sc5g8.26c, scbac-31e11.02c, scbac31e11.02c, sc4b10.10c, sdhA2, sdhB2, sdhA1, sdhB1, qcrB2, sdhA3, sdhB3, frdB1 and frdB2, where the genes sdhA, sdhB and sdhC are especially preferred.
[0124] The enzyme E15 is preferably encoded by genes selected from the group consisting of suclg1, suclg2, loc434885, cg10622, dmel-CG6255, flla3.3, f8115.30, mkd15.11, lsc1, lsc2, ae1211wp, afrl34cp, scsA, scsB, sucC and sucD.
[0125] Again, the nucleotide sequences of suitable genes of the enzymes E12 to E15, can also be found in the KEGG database, the NCBI database or the EMBL database.
[0126] In the event that the activity of one or more of the enzymes E12 to E15 is increased, it may also prove advantageous that the cell features an activity of one of the following enzymes E16 to E23 which is reduced in comparison with its wild type:
[0127] of an enzyme E16, which catalyzes the conversion of oxaloacetate into citrate;
[0128] of an enzyme E17, which catalyzes the conversion of malate into oxaloacetate;
[0129] of an enzyme E18, which catalyzes the conversion of succinyl-coenzyme A into succinate,
[0130] of an enzyme E19, which catalyzes the conversion of oxaloacetate into phosphoenolpyruvate, of an enzyme E20, which catalyzes the conversion of oxaloacetate into pyruvate,
[0131] of an enzyme E21, which catalyzes the conversion of oxaloacetate into aspartate,
[0132] of an enzyme E22, which catalyzes the conversion of malate into pyruvate,
[0133] of an enzyme E23, which catalyzes the conversion of pyruvate into acetate.
[0134] Cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is reduced: E16, E17, E18, E19, E20, E21, and E16E17E18E19E20E21E22E23.
[0135] In this context, it is especially preferred that the enzyme
[0136] E16 is a citrate synthase (EC 2.3.3.1 or EC 2.3.3.8),
[0137] E17, is a malate oxidase (EC 1.1.3.3),
[0138] E18 is a succinyl CoA hydrolase (EC 3.1.2.3),
[0139] E19 is a phosphoenolpyruvate carboxykinase (EC 4.1.1.49 or 4.1.1.32),
[0140] E20 is an oxaloacetate decarboxylase (EC 4.1.1.3),
[0141] E21 is an aspartate transaminase (EC 2.6.1.1),
[0142] E22 is a malate dehydrogenase (EC 1.1.1.38, EC 1.1.1.39 or EC 1.1.1.40),
[0143] E23 is a pyruvate dehydrogenase (EC 1.2.1.51).
[0144] The enzyme E16 is preferably encoded by genes selected from the group consisting of glt, cs, csl, cg3861, cts-1, f7f19.21, f4i1.16, t20n10.90, t20n10.100, t209.80, cit1, cit2, cit3, aar004cp, agr002wp, cshA, gltA, citZ, cit, prpC, cisY, cis, mmgD, citA, gltA1, gltA2, gltA3, cgl0829, prpC1, scd10.20, citA1, citA2, citA3, acly, cg8322, f5e6.2, k7jJ8.14 and citE, where gltA is most preferred.
[0145] The enzyme E19 is preferably encoded by genes selected from the group consisting of pckA, pck1, pck2, cg10924, cg17725, cg17725, pckG, ppcK, cgl2863, pck and 2sck36.02.
[0146] The enzyme E20 is preferably encoded by genes selected from the group consisting of oadA, oadB, oadC, oadG, oag3, eda, dcoA, oadA1, oadA2, pycB and mmdB.
[0147] The enzyme E21 is preferably encoded by genes selected from the group consisting of myn8.7, glt1, adr290wp, gltB, gltD, glt1, gls1, gitA, glt, glxD, gltD1, gltD2, gdh2, agl040Cp, gdhA1, gdhA, gdhA2, gluD, gluD1, gluD2, rocG, ypcA, gudB, t11i18.2, t2i1.150, mrg7.13, f19c24.7, gdh, gdh1, gdh2, gdh3, got1, got2, cg4233, cg8430, f23n19.17, f13j11.16, t26c19.9, f7f1.18, F10N7.200, t1611.170, f15n18.110, t20d1.70, aat1, aat2, ab1038wp, afr211cp, agx1, bna4, aatA, aatB, ybdL, aspC, yfbQ, aat, avtA1, avtA2, tyrB, avtA, avtB, argD1, argD2, aspB1, aspB2, aspB3, aspB, aspC1, aspC2, aspC3, aspC4, RS05143, aspAT, ywfG, yhdR, argD, mtnV, alaT, hisC, avtA1, avtA2, avtA3, cgl0240, cgl1103, cgl2599, cg12844, 2sck36.07c, sc9e12.21, sc2h4.04c, tyrB, gtp, gtp1, gtp2, cg1640, f20d23.34, f26f24.16, f24j13.15, t10d10.20 and agr085wp, where aspC, aatA, gdh, gudB, gdhA, gltB and gltD are especially preferred.
[0148] The enzyme E21 is preferably by genes selected from the group consisting of myn8.7, glt1, adr290wp, gltB, gltD, glt1, gls1, gltA, glt, glxD, gltD1, gltD2, gdh2, agl040Cp, gdhA1, gdhA, gdhA2, gluD, gluD1, gluD2, rocG, ypcA,
[0149] The enzyme E22 is preferably encoded by genes selected from the group consisting of me, me1, me2, me3, mae, mae1, mae2, sfcA, sfcA1, maeA, maeB, tme, yqkJ, ywkA, yqkJ, malS, ytsJ, mleA, mleS, mez, sce59.10c, 2sc7g11.23, malS1, malS2, dme, maeB1, maeB2, mdh, mdh1, mdh2, dmel_cg10120, dmel_cg10120, dmel-cg5889, f19k16.27, f6f22.7, t22p22.60, f18a17.1, mod1, tme, mao, cgl3007, malS and malE.
[0150] The enzyme E23 is preferably encoded by genes selected from the group consisting of me, me1, me2, me3, mae, mae1, mae2, sfcA, sfcA1, maeA, maeB, tme, yqkJ, ywkA, yqkJ, malS, ytsJ, mleA, mleS, mez, sce59.10c, 2sc7g11.23, malS1, malS2, dme, maeB1, maeB2, mdh, mdh1, mdh2, dmel_cgl0120, dmelcg10120, dmel-cg5889, f19k16.27, f6f22.7, t22p22.60, f18a17.1, mod1, tme, mao, cgl3007, malS and malE.
[0151] Furthermore, it is preferred in accordance with the invention that, in the event where the increased provision of succinyl-coenzyme A in the cell takes place by means of the above-described pathway (oxaloacetate malate→fumarate→succinyl-coenzyme A), the provision of reduction equivalents in the cell is also increased in a targeted manner.
[0152] One possibility of increasing the reduction equivalents consists in increasing the oxidative pentose phosphate pathway. In this context, it is especially preferred that the activities of glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and/or of 6-phosphogluconate dehydrogenase (EC 1.1.1.44), which is preferably encoded by the gnd gene, are increased while, if appropriate, simultaneously inhibiting glycolysis, for example by lowering the activity of glucose 6-phosphate isomerase, as described in WO-A-01/07626. In addition to, or instead of, the directed promotion of the pentose phosphate pathway, it may furthermore be preferred to provide reduction equivalents by supplying, to the cells, ethanol as the carbon source and by promoting, in the cells, the conversion of the ethanol into acetaldehyde by means of alcohol dehydrogenases (EC 1.1.1.1, EC 1.1.1.2, EC 1.1.1.71 or EC 1.1.99.8) and the further conversion of the acetaldehyde into acetyl coenzyme A by means of acetaldehyde dehydrogenases (EC 1.2.1.10). Again, suitable genes for alcohol dehydrogenases and acetaldehyde dehydrogenases, can be found in gene databases which are known to the skilled worker, such as, for example, the KEGG database, the NCBI database or the EMBL database.
[0153] A second pathway from oxaloacetate to succinyl-coenzyme A leads via citrate as intermediate. In this case, it is preferred in accordance with a second special embodiment of the above-described first, second or third alternative of the cell according to the invention that the cell, if appropriate in addition to an increased activity of the enzyme E10 or E11, features an activity of at least one of the following enzymes E13 to E16 and E24 to E26 which is increased in comparison with its wild type (see FIG. 8):
[0154] of an enzyme E16, which catalyzes the conversion of oxaloacetate into citrate;
[0155] of an enzyme E24, which catalyzes the conversion of citrate into isocitrate;
[0156] of an enzyme E25, which catalyzes the conversion of isocitrate into glyoxalate and succinate;
[0157] of an enzyme E26, which catalyzes the conversion of glyoxalate into malate;
[0158] of an enzyme E13, which catalyzes the conversion of malate into fumarate;
[0159] of an enzyme E14, which catalyzes the conversion of fumarate into succinate;
[0160] of an enzyme E15, which catalyzes the conversion of succinate into succinyl-coenzyme A.
[0161] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E13, E14, E15, E15, E24, E25, E26, E13E14, E13E15, E13E16, E13E24, E13E25, E13E26, E14E15, E14E16, E14E24, E14E25, E14E26, E15E16, E15E24, E15E25, E15E26 and E13E14E15E16E24E25E26, where E13E14E15E16E24E25E26 is most preferred.
[0162] In this context, it is especially preferred that the enzyme
[0163] E13 is a fumarate hydratase (EC 4.2.1.2),
[0164] E14 is a succinate dehydrogenase (EC 1.3.99.1 or EC 1.3.5.1) or a succinate quinone oxidoreductase (1.3.5.1),
[0165] E15 is a succinate coenzyme A ligase (EC 6.2.1.4 or EC 6.2.1.5),
[0166] E16 is a citrate synthase (EC 2.3.3.1 or EC 2.3.3.8),
[0167] E24 is an aconitate hydratase (EC 4.2.1.3) and
[0168] E25 is an isocitrate lyase (EC 4.1.3.1) and
[0169] E26 is a malate synthase (EC 2.3.3.9).
[0170] Preferred genes for the enzymes E13 to E16 are those which have already been described above in connection with the first pathway from oxaloacetate to succinyl-coenzyme A.
[0171] The enzyme E24 is preferably encoded by genes selected from the group consisting of aco1, aco2, ratireb, dmel-CG4706, dmel-CG4900, dmel-cg6342, cg9244, t3p4.5, f10m23.310, f4b14.100, ad1032Wp, afr629wp, acnA, acnB, acnC, acnD, rpfA, acnA1, acnA2, acnM, citB, leuC, cg11540, sacA, can and aco, where acnA and acnB are especially preferred.
[0172] The enzyme E25 is preferably encoded by genes selected from the group consisting of msd21.4, icl1, icl2, ad1066cp, agl057wp, aceA, icl, aceAa, aceAb, cgl0097 and cgl2331, where aceA is especially preferred. In accordance with a particular embodiment, genes which are preferred are those which code for an isocitrate lyase which is deregulated at the gene level or protein level.
[0173] The enzyme E26 is preferably encoded by genes selected from the group consisting of med24.5, mlsS1, acr268cp, masA, glcB, aceB, mls, glcB-1, glcB-2, cgl2329, masZ, aceB1, aceB2 and mas, where the aceB gene is especially preferred.
[0174] Again, the nucleotide sequences of suitable genes of the enzymes E24 to E26 can be found in the KEGG database, the NCBI database or the EMBL database.
[0175] When the provision of oxaloacetate from phosphoenolpyruvate or from pyruvate is promoted by increasing the activity of the enzyme E10 or E11, the succinate which is formed, besides glyoxalate, upon cleavage of the isocitrate by the isocitrate lyase may also be utilized for the formation of succinyl-coenzyme A. Furthermore, it may be advantageous in this second pathway from the oxaloacetate to the succinate to reduce the activity of an enzyme E27, which catalyzes the conversion of isocitrate into 2-oxoglutarate and which preferably takes the form of an isocitrate dehydrogenase (EC 1.1.1.41 or EC 1.1.1.42). Preferably, the isocitrate dehydrogenase takes the form of an enzyme which is encoded by a gene selected from the group consisting of idh1, idh2, cg7176, cg7176, cg7176, f20d21.16, f12p19.10, t15n1.80, idp1, idp2, idp3, aal022Wp, aer061Cp, idhC, idhM, icdA, icd, idh, icd1, icd2, leuB, citC, citC, cgl0664, leuB2, idh3A, idg3B, idh3G, cg12233, dmel-CG5028, dmel-CG6439, f6p23.14, f23e12.180, f8d20.160, f12e4.20, ad1223wp and afrl37cp, where icdA and citC are especially preferred.
[0176] A third pathway from the oxaloacetate to the succinyl-coenzyme A leads via 2-oxoglutarate as intermediate. In this case, it is preferred in accordance with a third special embodiment of the above-described first, second or third alternative of the cell according to the invention that the cell features an activity of at least one of the following enzymes E16, E24, E27 and E28 which is increased in comparison with its wild type, if appropriate in addition to an increased activity of the enzyme E10 or E11 (see FIG. 9):
[0177] of an enzyme E16, which catalyzes the conversion of oxaloacetate into citrate;
[0178] of an enzyme E24, which catalyzes the conversion of citrate into isocitrate;
[0179] of an enzyme E27, which catalyzes the conversion of isocitrate into 2-oxoglutarate;
[0180] of an enzyme E28, which catalyzes the conversion of 2-oxoglutarate into succinyl-coenzyme A.
[0181] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E15, E24, E27, E28, E16E24, E16E27, E16E28, E24E27, E24E28, E27E28, E16E24E27, E16E24E28, E24E27E28 and E16E24E27E28, where E16E24E27E28 is most preferred.
[0182] In this context, it is especially preferred that the enzyme
[0183] E16 is a citrate synthase (EC 2.3.3.1 or EC 2.3.3.8),
[0184] E24 is an aconitate hydratase (EC 4.2.1.3),
[0185] E27 is an isocitrate dehydrogenase (EC 1.1.1.41 or EC 1.1.1.42) and
[0186] E28 is a 2-oxoglutarate synthase (EC 1.2.7.3).
[0187] Preferred genes for the enzymes E16, E24 and E27 are those which have already been described above in connection with the first and second pathway from the oxaloacetate to the succinyl-coenzyme A.
[0188] The enzyme E28 is preferably encoded by genes selected from the group consisting of korA, korB, kor D, korA1, korA2, korB1, korB2, oorA, oorB, oorC, oorD, oforA, oforB, porA, porB, porA1, porA2, porA3, porA4, porG, porA1, porG2, porB1, porB2, porB3, SCD20.12c, SCD20.13c, SCAH10.34c, SCAH10.35c, korG, orA, orB, korA1 and korG2. Furthermore, E28 may also take the form of a dehydrogenase complex consisting of a plurality of subunits which have different enzymatic activities. In particular, it may take the form of a dehydrogenase complex comprising an oxoglutarate dehydrogenase (EC 1.2.4.2), a dihydrolipoyl dehydrogenase (EC 1.8.1.4) and a dihydrolipoyllysine-residue succinyl transferase (EC 2.3.1.61). In this context, the oxoglutarate dehydrogenase (EC 1.2.4.2) is preferably encoded by genes selected from the group consisting of ogdh, ghdhl, loc239017, mgc68800, mgc80496, cg11661, t22e16.70, mpA24.10, kgd1, aer374cp, sucA, odhA, kgdA and cgl1129, where sucA and odhA are especially preferred. The dihydrolipoyl dehydrogenase (EC 1.8.1.4) is preferably encoded by genes selected from the group consisting of dld, dld-prov, dldh, cg7430, t2j15.6, k14a17.6, at3g17240, mgd8.71pd1, afr512wp, dld1, 1pd, tb03.26j7.650, tb04.3m17.450, tb927.8.7380, tb08.10k10.200, lpdA, lpdG, lpdV, lpd3, acoD, IpdA1, lpdA2, lpdA3, odhL, pdhD, pdhD1, pdhD2, pdhD3, pdhD42, lpdAch1, lpdAch2, lpdAc, acoL, bfmbC, bkdD, cgl0366, cg10688, scm1.17c, pdhL, sck13.11, 1pdB2 and dld1, where lpd is especially preferred. In this context, the dihydrolipoyllysine-residue succinyl transferase (EC 2.3.1.61) is preferably encoded by genes selected from the group consisting of dlst, dlst-prov, mgc89125, dmel_CG5214, f10m23.250, k13p22.8, kgd2agl200wp, kgd2, odhB, sucB, aceF, kgdB, sucB1, sucB2, pdhC, dlaT, kgd, sc5F7.20 and sc4B10.24c, where sucB and odhB are especially preferred.
[0189] The nucleotide sequences of suitable genes of the enzyme E28 or of the abovementioned subunits of the enzyme E28, can, again, be found in the KEGG database, the NCBI datase or the EMBL database.
[0190] The above-described pathways from the oxaloacetate to the succinyl-coenzyme A depart from phosphoenolpyruvate or from pyruvate as substrate precursors. In this context, it may furthermore be preferred to genetically modify the cells in such a way that they are capable of providing especially large amounts of pyruvate or phosphoenolpyruvate starting from carbohydrates and/or from glycerol.
[0191] In the event that the cells are capable of utilizing glycerol as nutrient source, it is preferred that the cell according to the invention displays an activity of at least one, preferably all, of the following enzymes E29 to E42 which is increased in comparison with its wild type:
[0192] of an enzyme E29, which facilitates the diffusion of glycerol into the cell,
[0193] of an enzyme E30, which catalyzes the conversion of glycerol into glycerol 3-phosphate, of an enzyme E31, which catalyzes the conversion of glycerol 3-phosphate into dihydroxyacetone phosphate,
[0194] of an enzyme E32, which catalyzes the transfer of sulfur to the sulfur acceptor thioredoxin 1,
[0195] of an enzyme E33, which catalyzes the hydrolysis of phospholipids with formation of alcohols and glycerol,
[0196] of an enzyme E34, which catalyzes the transport of glycerol 3-phosphate into the cell in exchange for phosphate;
[0197] of an enzyme E35, which catalyzes the conversion of dihydroxyacetone phosphate into glyceraldehyde 3-phosphate,
[0198] of an enzyme E36, which catalyzes the conversion of glyceraldehyde 3-phosphate into 1,3-biphosphoglycerate,
[0199] of an enzyme E37, which catalyzes the conversion of 1,3-biphosphoglycerate into 3-phosphoglycerate,
[0200] of an enzyme E38, which catalyzes the conversion of 3-phosphoglycerate into 2-phosphoglycerate,
[0201] of an enzyme E39, which catalyzes the conversion of 2-phosphoglycerate into phosphoenolpyruvate,
[0202] of an enzyme E40, which catalyzes the conversion of phosphoenolpyruvate into pyruvate,
[0203] of an enzyme E41, which catalyzes the conversion of glycerol into dihydroxyacetone,
[0204] of an enzyme E42, which catalyzes the conversion of dihydroxyacetone into dihydroxyacetone phosphate.
[0205] In this context, cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is reduced: E29, E30, E31, E32, E33, E34, E35, E36, E37, E38, E39, E40, E41, E42, E29E30, E29E31, E29E32, E29E33, E29E34, E29E35, E29E36, E29E37, E29E38, E29E39, E29E40, E29E41, E29E42, E30E31, E30E32, E30E33, E30E34, E30E35, E30E36, E30E37, E30E38, E30E39, E30E40, E30E41, E30E42, E31E32, E31E33, E31E34, E31E35, E31E36, E31E37, E31E38, E31E39, E31E40, E31E41, E31E42, E32E33, E32E34, E32E35 E32E36, E32E37, E32E38, E32E39, E32E40, E32E41, E32E42, E33E34, E33E35, E33E36, E33E37, E33E38, E33E39, E33E40, E34E41, E33E42, E34E35, E34E36, E34E47, E34E38, E34E39, E34E40, E34E41, E34E42, E35E36, E35E37, E35E38, E35E39, E35E40, E35E41, E35E42, E36E37, E36E38, E36E39, E36E40, E36E41, E36E42, E37E38, E37E39, E37E40, E37E41, E37E42, E38E39, E39E40, E39E41, E39E42, E40E41, E40E42, E41E42 and E29E30E31E32E33E34E35E36E37E- 38E39-E40E41E42.
[0206] In this context, it is especially preferred that the enzyme
[0207] E29 is an aquaglyceroporin (glycerol facilitator) which is preferably encoded by the glpF gene,
[0208] E30 is a glycerol kinase (EC 2.7.1.30) which is preferably encoded by the glpK gene,
[0209] E31 is a glycerol 3-phosphate dehydrogenase (EC 1.1.99.5), preferably an FAD-dependent glycerol 3-phosphate dehydrogenase, where the glycerol 3-phosphate dehydrogenase is preferably encoded by the gipA gene, the glpB gene, the glpC gene or the glpD gene, especially preferably by the glpD gene,
[0210] E32 is a sulfur transferase which is encoded by the glpE gene,
[0211] E33 is a glycerol phosphodiesterase (EC 3.1.4.46) which is preferably encoded by the glpQ gene,
[0212] E34 is a glycerol 3-phosphate permease which is preferably encoded by the glpT gene,
[0213] E35 is a triose phosphate isomerase (EC 5.3.1.1),
[0214] E36 is a glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12),
[0215] E37 is a phosphoglycerate kinase (EC 2.7.2.3),
[0216] E38 is a phosphoglycerate mutase (EC 5.4.2.1),
[0217] E39 is an enolase (EC 4.2.1.11),
[0218] E40 is a pyruvate kinase (EC 2.7.1.40),
[0219] E41 is a glycerol dehydrogenase (EC 1.1.1.6) which is preferably encoded by the gldA gene, and
[0220] E42 is a dihydroxyacetone kinase (EC 2.7.1.29) which is preferably encoded by the dhaK gene.
[0221] The gene sequences of the abovementioned enzymes can, again, be found in the gene databases which are known to the skilled worker, in particular the KEGG database, the NCBI database or the EMBL database.
[0222] Furthermore, the gap gene, which codes for glyceraldehyde 3-phosphate dehydrogenase (Eikmanns (1992), Journal of Bacteriology 174: 6076-6086), the tpi gene, which codes for triose phosphate isomerase (Eikmanns (1992), Journal of Bacteriology 174: 6076-6086), and the pgk gene, which codes for 3-phosphoglycerate kinase (Eikmanns (1992), Journal of Bacteriology 174: 6076-6086), are also known from other sources.
[0223] Using the known genes of the enzymes E29 to E42, it is possible to prepare genetically modified cells in which at least one, preferably at least two, more preferably at least three and most preferably all activities of the enzymes E29 to E42 has been increased by means of the techniques (mutation of the enzyme or increase in the expression of the enzyme) described at the outset in connection with the enzyme E1. These cells are capable of being cultured in the presence of glycerol as the only carbon source (or else together with carbohydrates as further carbon source).
[0224] In addition to increasing one or more of the enzymatic activities E29 to E42, it may, in the event that the cell is capable of utilizing glycerol as carbon source, also be advantageous when the following genes are expressed, preferably heterologously expressed, in the cells according to the invention:
[0225] the glpG gene or the 3925 gene,
[0226] the glpX gene,
[0227] the dhaR gene, the ycgU gene or the b1201 gene,
[0228] the fsa gene, the mipB gene, the ybiZ gene or the B0825 gene,
[0229] the talC gene, the fsaB gene, the yijG gene or the b3946 gene.
[0230] Again, the nucleotide sequences of these genes can be found in the KEGG database, the NCBI database or the EMBL database.
[0231] In the event that the cells are capable of utilizing carbohydrates as nutrient source, it is preferred that the cell according to the invention features an activity of at least one, preferably of all, of the following enzymes E43 to E45 and E36 to E40 which is increased in comparison with its wild type:
[0232] of an enzyme E43, which catalyzes the conversion of α-D-glucose 6-phosphate into β-D-fructose 6-phosphate, of an enzyme E44, which catalyzes the conversion of β-D-fructose 6-phosphate into β-D-fructose 1,6-biphosphate,
[0233] of an enzyme E45, which catalyzes the conversion of
[0234] β-D-fructose 1,6-biphosphate to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate,
[0235] of an enzyme E36, which catalyzes the conversion of glyceraldehyde 3-phosphate into 1,3-biphosphoglycerate,
[0236] of an enzyme E37, which catalyzes the conversion of 1,3-biphosphoglycerate into 3-phosphoglycerate,
[0237] of an enzyme E38, which catalyzes the conversion of 3-phosphoglycerate into 2-phosphoglycerate,
[0238] of an enzyme E39, which catalyzes the conversion of 2-phosphoglycerate into phosphoenolpyruvate, and
[0239] of an enzyme E40, which catalyzes the conversion of phosphoenolpyruvate into pyruvate.
[0240] In this context genetically modified cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E36, E37, E38, E39, E40, E43, E44, E45, E36E37, E36E38, E36E39, E36E40, E36E43, E36E44, E36E45, E37E38, E37E39, E37E40 E37E43, E37E44, E37E45, E38E39, E38E40, E38E43, E38E44, E38E45, E39E40 E39E43, E39E44, E39E45, E40E43, E40E44, E40E45, E43E94, E43E45, E44E45 and E36E37E38E39E40E43E44E45
[0241] In this context, it is especially preferred that the enzyme
[0242] E43 is a glucose 6-phosphate isomerase (EC 5.3.1.9),
[0243] E44 is a 6-phosphofructo kinase (EC 2.7.1.11),
[0244] E45 is a fructose bisphosphate aldolase (EC 4.1.2.13),
[0245] E36 is a glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12),
[0246] E37 is a phosphoglycerate kinase (EC 2.7.2.3),
[0247] E38 is a phosphoglycerate mutase (EC 5.4.2.1),
[0248] E39 is an enolase (EC 4.2.1.11) and
[0249] E40 is a pyruvate kinase (EC 2.7.1.40).
[0250] Again, the nucleotide sequences of these genes can be found be found in the KEGG database, the NCBI database or the EMBL database.
[0251] In the event that the cell is capable of utilizing carbohydrates as carbon source, it is furthermore preferred to promote not only the abovementioned enzymes E43 to E45 and E36 to E40, but also the uptake of glucose into the cells, for example by increasing the activity of enzymes of the phosphotransferase system, in particular those enzymes which are encoded by ptsI, ptsH and ptsM genes, or by enhancing glucokinase (EC 2.7.1.2), which is preferably encoded by the glk gene. In this context, reference is made in particular to U.S. Pat. No. 6,680,187, U.S. Pat. No. 6,818,432, U.S. Pat. No. 6,913,910 and U.S. Pat. No. 6,884,614, whose disclosure content with regard to the possibilities for overexpressing the ptsI, ptsH, ptsM and glk genes is hereby incorporated by reference and forms part of the disclosure of the present invention. In the event that carbohydrates act as carbon source, it may also be advantageous to promote the pentose phosphate pathway in a targeted manner, for example by increasing the activity of glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and of 6-phosphogluconate dehydrogenase (EC 1.1.1.44), which is preferably encoded by the gnd gene, while, if appropriate, simultaneously inhibiting glycolysis, for example by weakening the activity of glucose 6-phosphate isomerase, as is described in WO-A-01/07626.
[0252] In the event that, according to the special embodiment of the cell according to the invention where methylmalonate semialdehyde is formed as precursor and succinyl-coenzyme A as intermediate, the cells form 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid via oxaloacetate and pyruvate as intermediates, it may furthermore be preferred to reduce the activity of at least one, preferably of all, of the following enzymatic activities in the cell:
[0253] of an enzyme which catalyzes the conversion of oxaloacetate into phosphoenolpyruvate, such as, for example, phosphoenylpyruvate carboxykinase (EC 4.1.1.49) (see also DE-A-199 50 409),
[0254] of an enzyme which catalyzes the conversion of pyruvate into acetate such as, for example, pyruvate oxidase (EC 1.2.2.2) (see also DE-A-199 51 975),
[0255] of an enzyme which catalyzes the conversion of α-D-glucose 6-phosphate into βD-fructose 6-phosphate (see also U.S. Ser. No. 09/396,478),
[0256] of an enzyme which catalyzes the conversion of pyruvate into lactate such as, for example, 1-lactate dehydrogenase (EC 1.1.1.27) or lactate-malate transhydrogenase (EC 1.1.99.7),
[0257] of an enzyme which catalyzes the conversion of pyruvate into acetyl-coenzyme A such as, for example, pyruvate dehydrogenase (EC 1.2.1.51),
[0258] of an enzyme which catalyzes the conversion of pyruvate into acetyl phosphate such as, for example, pyruvate oxidase (EC 1.2.3.3),
[0259] of an enzyme which catalyzes the conversion of pyruvate into acetate, such as, for example, pyruvate dehydrogenase (EC 1.2.2.2),
[0260] of an enzyme which catalyzes the conversion of pyruvate into phosphoenolpyruvate such as, for example, phosphoenolpyruvate synthase (EC 2.7.9.2) or pyruvate, phosphate dikinase (EC 2.7.9.1),
[0261] of an enzyme which catalyzes the conversion of pyruvate into alanine such as, for example, alanine transaminase (2.6.1.2) or alanine-oxo-acid transaminase (EC 2.6.1.12), and/or
[0262] of an enzyme which converts pyruvate into acetolactate such as, for example, acetohydroxy acid synthase (EC 2.2.1.6).
[0263] Cells which are especially preferred in accordance with the invention and which are capable of forming 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxybutyric acid from carbohydrates as carbon source via succinyl-coenzyme A as intermediate and in which one or more of the abovementioned enzymatic activities, in particular one of the enzymatic activities E1 to E45, more preferably the enzymatic activities E1, E1E2E3E4, E1E4E5E6E7 or and E1E4E5E7, can be increased are those microorganisms which have been described by Bennett et al., Metab. Eng. (2005), 7 (3), pages 229 to 239, Bennett et al., Biotechnol. Bioeng. (2005), 90 (6), pages 775 to 779, Bennett et al., Biotechnol. Prog. (2005), 21 (2), pages 358 to 365, Bennett et al. (2005), Appl. Microbiol. Biotechnol., 67 (4), pages 515 to 523, Vemuri et al. (2002), Applied and Environmental Microbiology 68 (4), pages 1715 to 1727 and in U.S. Pat. No. 6,455,284.
[0264] If, according to the first special embodiment of the cell according to the invention, the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoates based on 3-hydroxyisobutyric acid starting from L-glutamate as carbon source takes place via succinyl-coenzyme A as intermediate, it is, in a further special embodiment of the cell according to the invention, in which methylmalonat semialdehyde is formed as precursor and succinyl-coenzyme A as intermediate, furthermore preferred in accordance with the invention that it features an activity of at least one of the, preferably of the two, following enzymes E28 and E46 which is increased in comparison with its wild type (see FIG. 10):
[0265] of an enzyme E46, which catalyzes the conversion of L-glutamate into 2-oxoglutarate;
[0266] of an enzyme E28, which catalyzes the conversion of 2-oxoglutarate into succinyl-coenzyme A.
[0267] In this context, it is especially preferred that the enzyme
[0268] E46 is a glutamate synthase (EC 1.4.1.13 or EC 1.4.1.14), a glutamate dehydrogenase (EC 1.4.1.2, EC 1.4.1.3 or EC 1.4.1.4) or an aspartate transaminase (EC 2.6.1.1 or EC 2.6.1.2) and
[0269] E28 is a 2-oxoglutarate synthase (EC 1.2.7.3).
[0270] Preferred as enzyme E28 are those which have already been mentioned at the outset as preferred enzymes E28.
[0271] The enzyme E46 is preferably encoded by the genes selected from the group consisting of: myn8, glt1, adr290wp, gltB, gltD, yeiT, aegA, ygfT, gltD-1, gltD-2, glt1, glt2, gls1, gltA, glt, glxD, gltA, yerD, cgl0184, cgl0185, sc3c9.12, gdh1, gdh2, agl40cp, gdhA, gdhA1, gdhA2, gluD, rocG, ypcA, gudB, gluD, gdhA, gdhA2, gdh, gdhA-1, gdhA2-2, gdhA-3, gluD1, gluD2, glud1-prov, glud1a, t11I18.2, t2I1.150, mrg7.13, got1, got2, caspat, got2-prov, xr406-prov, 406-prov, cg4233, cg4233, cg8430, cg8430, f23n19.17, f13j11.16, t26c19.9, f7f1.18, f10n7.200, t1611.170, f15n18.110, t20d1.70, aat, aat1, aat2, ab1038wp, afr211cp, agx1, bnA4, aatA, aatB, ybdL, aspC, yfbQ, ydcR, avtA2, aspC-1, aspC-2, aspC-3, aspC-4, aspB, aspB-1, aspB-2, aspB-3, aspB-4, argD1, argD2, aatAc, ywfG, mtnV, alaT, avtA1, avtA2, avtA3, cgl0240, cgl1103, cgl2599, cgl2844, dapC, 2sck36.07c, sc9e12.21, sc2h4.04c, aspB1, aspB2, aspB3, tyrB, gpt, gpt1, gpt2, mgc82097, cgl640, c32f10.8, f20d23.34, f26f24.16, f24j13.15, t10d10.20 or agrwp.
[0272] Again, the nucleotide sequences of these genes can be found be found in the KEGG database, the NCBI database or the EMBL database.
[0273] In accordance with a second special embodiment of the cell according to the invention, where the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via methylmalonate semialdehyde as precursor, it is preferred that the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoate based on 3-hydroxyisobutyric acid takes place via propionyl-coenzyme A as intermediate, where the cell is capable of preferentially utilizing carbohydrates, glycerol, methane or methanol as carbon source. In this context, a variety of pathways exist for arriving at 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, departing from propionyl-coenzyme A.
[0274] In accordance with a first alternative of this second special embodiment of the cell according to the invention, the formation of intermediate propionyl-coenzyme A takes place via acetyl-coenzyme A as further intermediate. In this context, it is especially preferred that the cell features an activity of at least one of the following enzymes E4, E5 and E47 to E52 which is increased in comparison with its wild type (see FIG. 11):
[0275] of an enzyme E47, which catalyzes the conversion of acetyl-coenzyme A into malonyl-coenzyme A;
[0276] of an enzyme E48, which catalyzes the conversion of malonyl-coenzyme A into malonate semialdehyde;
[0277] of an enzyme E49, which catalyzes the conversion of malonate semialdehyde into 3-hydroxypropionate;
[0278] of an enzyme E50, which catalyzes the conversion of 3-hydroxypropionate into 3-hydroxypropionyl-coenzyme A;
[0279] of an enzyme E51, which catalyzes the conversion of 3-hydroxypropionyl-coenzyme A into acryloyl-coenzyme A;
[0280] of an enzyme E52, which catalyzes the conversion of acryloyl-coenzyme A into propionyl-coenzyme A;
[0281] of an enzyme E5, which catalyzes the conversion of propionyl-coenzyme A into methylmalonate semialdehyde;
[0282] of an enzyme E4, which catalyzes the conversion of methylmalonate semialdehyde into 3-hydroxyisobutyrate.
[0283] In this context, genetically modified cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E47, E48, E49, E50, E51, E52, E4, E5 and E47E48E49E50E51E52E4E5.
[0284] Furthermore, it is particularly preferred in this context that the enzyme
[0285] E4 is a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) or a 3-hydroxyacyl-coenzyme A dehydrogenase (EC 1.1.1.35),
[0286] E5 is a methylmalonate-semialdehyde dehydrogenase (EC 1.2.1.27),
[0287] E47 is a malonyl-coenzyme A decarboxylase (EC 4.1.1.9), a malonate-coenzyme A transferase (EC 2.8.3.3), a methylmalonyl-coenzyme A carboxy-transferase (EC 2.1.3.1) or an acetyl-coenzyme A carboxylase (EC 6.4.1.2),
[0288] E48 is a malonate-semialdehyde dehydrogenase (EC 1.2.1.18),
[0289] E49 is a 3-hydroxypropionate dehydrogenase (EC 1.1.1.59),
[0290] E50 is a 3-hydroxyisobutyryl-coenzyme A hydrolase (EC 3.1.2.4),
[0291] E51 is an enoyl-coenzyme A hydratase (EC 4.2.1.17) and
[0292] E52 is an acyl-coenzyme A dehydrogenase (EC 1.3.99.3).
[0293] Preferred genes for the enzymes E4 and E5 are those which have already been described above in connection with the first special embodiment of the cell according to the invention.
[0294] The enzyme E47 is preferably encoded by genes selected from the group consisting of mlycd, t19 b17.4, tb08.2904.110, matA, acac, acaca, acacb, f5j5.21, f15c21.2, t8p21.5, acc1, aar071wp, accA, accB, accC, accD, accC1, accC2, mmdA, fabG, accD1, accD2, accD3, cgl0831, accBC, dtsR1, accDA, scc24.16c and cgl1327, where accA, accC and accD are most preferred.
[0295] The enzyme E48 is preferably encoded by the iolD gene.
[0296] The enzyme E51 is preferably encoded by genes selected from the group consisting of echS1, ehhadh, hadha, echs1-prov, cg4389, cg4389, cg6543, cg6984, cg8778, ech-1, ech-2, ech-3, ech-4, ech-5, ech-6, ech-7, FCAALL.314, fcaall.21, fox2, eci1, eci2, paaF, paaG, yfcX, fadB, faoA, rpfF, phaA, phaB, echA1, echA2, echA3, echA4, echA5, echA6, echA7, echA8, echA9, echA9, echA10, echA11, echA12, echA13, echA14, echA15, echA16, echA17, echA18, echA19, echA20, echA21, fad-1, fad-2, fad-3, dcaE, hcaA, fadJ, rsp0671, rsp0035, rsp0648, rsp0647, rs03234, rs03271, rs04421, rs04419, rs02820, rs02946, paaG1, paaG2, paaG3, ech, pksH, ydbS, eccH1, eccH2, pimF, fabJ1, fabJ2, caiD2, ysiB, yngF, yusL, fucA, cgl0919, scf41.23, scd10.16, sck13.22, scp8.07c, stbac16h6.14, sc5f2a.15, sc6a5.38, hbd-1, hbd-2, hdb-3, hdb-4, hdb-5, hdb-6, hdb-7, hdb-8, hdb-9, hdb-10, fad-1, fad-2, fad-3, fad-4, fad-5, paaF-1, paaF-2, paaF-3, paaF-4, paaF-5, paaF-6, paaF-7 and crt.
[0297] The enzyme E52 is preferably encoded by genes selected from the group consisting of acadl, acadm, acad10, acad11, acadm-prov, acadl-prov, mgc81873, cg12262, cg4703, cg4860, f3e22.5, af1213wp, acdC, fadE13, acd-1, acd-2, acd-3, acd-4, acd-5, acd-6, acd-7, acd-8, acd-9, acd-10, acd-11, acd-12, acd, fadE1, fadE2, fadE3, fadE4, fadE5, fadE6, fadE7, fadE13, fadE14, fadE15, fadE16, fadE17, fadE18, fadE19, fadE20, fadE21, fadE22, fadE23, fadE26, fadE27, fadE30, fadE31, fadE33, fadE35, fadE38, fadE45, fadE, caiA, aidB, RSp0036, RS03588, mmgC, acdA-3, bcd, acdA, acdH1, acdH2, acdH3, aidB, acdI and acdH.
[0298] The nucleotide sequences of suitable genes for the enzymes E47 to E52, in particular also of the enzymes E49 and E50, can be found in the KEGG database, the NCBI database or the EMBL database.
[0299] According to a second alternative of this second special embodiment of the cell according to the invention, the formation of the intermediate propionyl-coenzyme A also takes place via acetyl-coenzyme A as further intermediate, where, according to this alternative, the propionyl-coenzyme A is not converted directly into the methylmalonate semialdehyde, but via methylmalonyl-coenzyme A. In this context, it is especially preferred that the cell features an activity of at least one of the following enzymes E2 to E4, E6, E7 and E47 to E52 which is increased in comparison with its wild type (see FIG. 12):
[0300] of an enzyme E47, which catalyzes the conversion of acetyl-coenzyme A into malonyl-coenzyme A;
[0301] of an enzyme E48, which catalyzes the conversion of malonyl-coenzyme A into malonate semialdehyde;
[0302] of an enzyme E49, which catalyzes the conversion of malonate semialdehyde into 3-hydroxypropionate;
[0303] of an enzyme E50, which catalyzes the conversion of 3-hydroxypropionate into 3-hydroxypropionyl-coenzyme A;
[0304] of an enzyme E51, which catalyzes the conversion of 3-hydroxypropionyl-coenzyme A into acryloyl-coenzyme A;
[0305] of an enzyme E52, which catalyzes the conversion of acryloyl-coenzyme A into propionyl-coenzyme A;
[0306] of an enzyme E7, which catalyzes the conversion of propionyl-coenzyme A into (S)-methylmalonyl-coenzyme A;
[0307] of an enzyme E6, which catalyzes the conversion of (S)-methylmalonyl-coenzyme A into (R)-methylmalonyl-coenzyme A;
[0308] of an enzyme E2, which catalyzes the conversion of (R)-methylmalonyl-coenzyme A into methyl malonate;
[0309] of an enzyme E3, which catalyzes the conversion of methyl malonate into methylmalonate semialdehyde;
[0310] of an enzyme E4, which catalyzes the conversion of methylmalonate-semialdehyde into 3-hydroxyisobutyrate.
[0311] In this context, genetically modified cells which are especially preferred according to the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E2, E3, E4, E5, E47, E48, E49, E50, E51, E52 and E2E3E4E6E7E47E48E49E50E51E52.
[0312] Preferred enzymes and genes of these enzymes are those genes and enzymes which have already been mentioned above in connection with the enzymes E2 to E4, E6, E7 and E47 to E52.
[0313] According to a third alternative of this first alternative of the second special embodiment of the cell according to the invention, the formation of the intermediate propionyl-coenzyme A also takes place via acetyl-coenzyme A as further intermediate, where, according to this alternative, the propionyl-coenzyme A is, again, not converted directly into methylmalonate-semialdehyde, but via (R)-methylmalonyl-coenzyme A (and not via (S)-methylmalonyl-coenzyme A). In this context, it is especially preferred that the cell features an activity of at least one of the following enzymes E2 to E4, E7 and E47 to E52 which is increased in comparison with its wild type (see FIG. 13):
[0314] of an enzyme E47, which catalyzes the conversion of acetyl-coenzyme A into malonyl-coenzyme A;
[0315] of an enzyme E48, which catalyzes the conversion of malonyl-coenzyme A into malonate semialdehyde;
[0316] of an enzyme E49, which catalyzes the conversion of malonate semialdehyde into 3-hydroxypropionate;
[0317] of an enzyme E50, which catalyzes the conversion of 3-hydroxypropionate into 3-hydroxypropionyl-coenzyme A;
[0318] of an enzyme E51, which catalyzes the conversion of 3-hydroxypropionyl-coenzyme A into acryloyl-coenzyme A;
[0319] of an enzyme E52, which catalyzes the conversion of acryloyl-coenzyme A into propionyl-coenzyme A;
[0320] of an enzyme E7, which catalyzes the conversion of propionyl-coenzyme A into methylmalonyl-coenzyme A;
[0321] of an enzyme E2, which catalyzes the conversion of methylmalonyl-coenzyme A into methylmalonate;
[0322] of an enzyme E3, which catalyzes the conversion of methyl malonate into methylmalonate-semialdehyde;
[0323] of an enzyme E4, which catalyzes the conversion of methylmalonate-semialdehyde into 3-hydroxyisobutyrate.
[0324] In this context, genetically modified cells which are especially preferred according to the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E2, E3, E4, E7, E47, E48, E49, E50, E51, E52 and E2E3E4E7E47E48E49E50E51E.sub- .52.
[0325] Preferred enzymes and genes of these enzymes are, again, those genes and enzymes which have already been mentioned above in connection with the enzymes E2 to E4, E7 and E47 to E52.
[0326] According to a fourth alternative of the second special embodiment of the cell according to the invention, the formation of the intermediate propionyl-coenzyme A also takes place via acetyl-coenzyme A as further intermediate, where, according to this alternative, acetoacetyl-coenzyme A is formed as intermediate. In this context, it may be preferred that the cell features an activity of at least one of the following enzymes E8 and E53 to E61 which is increased in comparison with its wild type:
[0327] of an enzyme E53, which catalyzes the conversion of acetyl-coenzyme A into acetoacetyl-coenzyme A;
[0328] of an enzyme E54, which catalyzes the conversion of acetoacetyl-coenzyme A into 3-hydroxybutanoyl-coenzyme A;
[0329] of an enzyme E55, which catalyzes the conversion of 3-hydroxybutanoyl-coenzyme A into crotonyl-coenzyme A;
[0330] of an enzyme E56, which catalyzes the conversion of crotonyl-coenzyme A into butyryl-coenzyme A;
[0331] of an enzyme E57, which catalyzes the conversion of butyryl-coenzyme A into ethylmalonyl-coenzyme A;
[0332] of an enzyme E58, which catalyzes the conversion of ethylmalonyl-coenzyme A into methylsuccinyl-coenzyme A;
[0333] of an enzyme E59, which catalyzes the conversion of methyl succinyl-coenzyme A isobutyryl-coenzyme A;
[0334] of an enzyme E60, which catalyzes the conversion of isobutyryl-coenzyme A into methacrylyl-coenzyme A;
[0335] of an enzyme E61, which catalyzes the conversion of methacrylyl-coenzyme A into 3-hydroxyisobutyryl-coenzyme A;
[0336] of an enzyme E8, which catalyzes the conversion of 3-hydroxyisobutyryl-coenzyme A into 3-hydroxyisobutyrate.
[0337] In this context, genetically modified cells which are especially preferred according to the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E8, E53, E54, E55, E56, E57, E58, E59, E60, E61 and E8E53E54E55E56E57E58E59E60E.- sub.61.
[0338] This metabolic pathway and the enzymes which play a role in this metabolic pathway are described, for example, in Korotkova et al., Journal of Bacteriology (2002), pages 1750 to 1758.
[0339] According to a fifth alternative of the second special embodiment of the cell according to the invention, the formation of the intermediate propionyl-coenzyme A takes place via, again, acetyl-coenzyme A as further intermediate, where, according to this alternative, acetoacetyl-coenzyme A is formed as further intermediate but where, in this case, ethylmalonyl-coenzyme A is formed directly from crotonyl-coenzyme A. In this context, it may be preferred that the cell features an activity of at least one of the following enzymes E8 and E53 to E56 and E62 to E65 which is increased in comparison with its wild type (see FIG. 14):
[0340] of an enzyme E53, which catalyzes the conversion of two acetyl-coenzyme A units into acetoacetyl-coenzyme A;
[0341] of an enzyme E54, which catalyzes the conversion of acetoacetyl-coenzyme A into 3-hydroxybutyryl-coenzyme A;
[0342] of an enzyme E55, which catalyzes the conversion of 3-hydroxybutyryl-coenzyme A into crotonyl-coenzyme A;
[0343] of an enzyme E56, which catalyzes the conversion of crotonyl-coenzyme A into ethylmalonyl-coenzyme A;
[0344] of an enzyme E62, which catalyzes the conversion of ethylmalonyl-coenzyme A into methylsuccinyl-coenzyme A;
[0345] of an enzyme E63, which catalyzes the conversion of methylsuccinyl-coenzyme A into mesaconyl-coenzyme A;
[0346] of an enzyme E64, which catalyzes the conversion of mesaconyl-coenzyme A into β-methylmalyl-coenzyme A;
[0347] of an enzyme E65, which catalyzes the conversion of β-methylmalyl-coenzyme A into glyoxylate and propionyl-coenzyme A.
[0348] Then, from propionyl-coenzyme A can in the above-described manner (increasing the activity of one or more of the enzymes E7, E2, E3 and E4, increasing the activity of one or more of the enzymes E7, E6, E2, E3 and E4, or increasing the activity of one of the, or of both, enzymes E4 and E5).
[0349] In this context, it is especially preferred that the enzyme
[0350] E53 is a β-ketothiolase (EC 2.3.1.9),
[0351] E54 is an acetoacetyl-coenzyme A reductase (an EC 1.1.1.36),
[0352] E55 is an enoyl-coenzyme A hydratase (EC 4.2.1.17),
[0353] E56 is a crotonyl-coenzyme A decarboxylase,
[0354] E62 is an ethylmalonyl-coenzyme A mutase (EC 5.4.99.2),
[0355] E63 is a methylsuccinyl-coenzyme A dehydrogenase,
[0356] E64 is a mesaconyl-coenzyme A hydratase, and
[0357] E65 is a β-methylmalyl/L-malyl-coenzyme A lyase.
[0358] The enzyme E53 is preferably encoded by genes selected from the group consisting of acat1, acat2, loc484063, loc489421, mgc69098, mgc81403, mgc81256, mgc83664, kat-1, erg10, ygeF, atoB, fadAx, phbA-1, phbA-2, atoB-2, pcaF, pcaF-2, phb-A, bktB, phaA, tioL, thlA, fadA, paaJ, phbAf, pimB, mmgA, yhfS, thl, vraB, thl, mvaC, thiL, paaJ, fadA3, fadA4, fadA5, fadA6, cgl12392, catF, sc8f4.03, thiL1, thiL2, acaB1, acaB2, acaB3, acaB4 or, where acat1, acat2, atoB and phbA and the corresponding gene from Rhodobacter sphaeroides are especially preferred.
[0359] The enzyme E54 is preferably encoded by genes selected from the group consisting of phbB, fabG, phbN1, phbB2 or cgl12444, where phbB is especially preferred and the corresponding gene from Rhodobacter sphaeroides is especially preferred.
[0360] The enzyme E55 is preferably encoded by genes selected from the group consisting of echS1, ehhadh, hadha, echs1-prov, Das Enzym E55 wird vorzugsweise von Genen ausgewahlt aus der Gruppe bestehend aus echS1, ehhadh, hadha, echS1-prov, cg4389, cg4389, cg6543, cg6984, cg8778, ech-1, ech-2, ech-3, ech-4, ech-5, ech-6, ech-7, FCAALL.314, fcaall.21, fox2, eci1, eci2, paaF, paaG, yfcX, fads, faoA, rpfF, phaA, phaB, echA1, echA2, echA3, echA4, echA5, echA6, echA7, echA8, echA9, echA9, echA10, echA11, echA12, echA13, echA14, echA15, echA16, echA17, echA18, echA19, echA20, echA21, fad-1, fad-2, fad-3, dcaE, hcaA, fadJ, rsp0671, rsp0035, rsp0648, rsp0647, rs03234, rs03271, rs04421, rs04419, rs02820, rs02946, paaG1, paaG2, paaG3, ech, pksH, ydbS, eccH1, eccH2, pimF, fabJ1, fabJ2, caiD2, ysiB, yngF, yusL, fucA, cgl0919, scf41.23, scd10.16, sck13.22, scp8.07c, stbac16h6.14, sc5f2a.15, sc6a5.38, hbd-1, hbd-2, hdb-3, hdb-4, hdb-5, hdb-6, hdb-7, hdb-8, hdb-9, hdb-10, fad-1, fad-2, fad-3, fad-4, fad-5, paaF-1, paaF-2, paaF-3, paaF-4, paaF-5, paaF-6, paaF-7 and crt
where the corresponding gene from Rhodobacter sphaeroides is especially preferred.
[0361] The enzyme which is preferably employed as enzyme E56 is an enzyme from Rhodobacter sphaeroides which is encoded by the DNA sequence with the SEQ ID No 05 and which has the amino acid sequence as shown in SEQ ID No 06.
[0362] Suitable genes for the enzyme E62 are selected from the group consisting of mut, mutA, mutB, sbm, sbmA, sbmB, sbm5, bhbA, mcmA, mcmA1, mcmA2, mcmB, mcm1, mcm2, mcm3, icmA, meaA1 and meaA2, where, again, the corresponding gene from Rhodobacter sphaeroides is especially preferred.
[0363] Preferred genes for the enzymes E63, E64 and E65 are, in particular, the genes for these enzymes from Rhodobacter sphaeroides.
[0364] Further examples of nucleotide sequences of the abovementioned genes can also be found in the KEGG database, the NCBI database or the EMBL database, inter alia.
[0365] As has already been explained above, the first alternative of the second preferred embodiment cell according to the invention generates 3-hydroxyisobutyric acid or the polyhydroxyalkanoates based on 3-hydroxyisobutyric acid via propionyl-coenzyme A and acetyl-coenzyme A as intermediates. In this context, it may be meaningful, in principle, to influence not only one or more of the abovementioned enzymatic activities E2 to E8 and E47 to E65, but also those enzymatic activities which bring about an increase in the formation of acetyl-coenzyme A in the cell.
[0366] In the event that 3-hydroxyisobutyric acid is formed from carbohydrates or glycerol as carbon source, it may be preferred that the cell features an increased activity in an enzyme E66, which catalyzes the conversion of pyruvate into acetyl-coenzyme A. This enzyme E66 preferably takes the form of a pyruvate dehydrogenase (EC 1.2.1.51).
[0367] In the event that 3-hydroxyisobutyric acid is formed from C1-carbon sources such as, for example, methane or methanol, it may be preferred that the cell features an activity of at least one of the enzymes E67 to E71 which is increased in comparison with its wild type:
[0368] of an enzyme E67, which catalyzes the conversion of methane into methanol;
[0369] of an enzyme E68, which catalyzes the conversion of methanol into formaldehyde;
[0370] of an enzyme E69, which catalyzes the conversion of formaldehyde into 5,10-methylenetetrahydrofolate;
[0371] of an enzyme E70, which catalyzes the conversion of 5,10-methylenetetrahydrofolate into 5-methyltetrahydrofolate;
[0372] of an enzyme E71, which catalyzes the conversion of 5-methyltetrahydrofolate into acetyl-coenzyme A.
[0373] In this context, it is especially preferred that the enzyme
[0374] E67 is a methane monooxygenase (EC 1.14.13.25),
[0375] E68 is a methanol dehydrogenase (EC 1.1.1.244),
[0376] E69 is a methylmalonate-semialdehyde dehydrogenase (EC 1.2.1.27),
[0377] E70 is a methylenetetrahydrofolate reductase (EC 1.5.1.20),
[0378] E71 is a carbon monoxide dehydrogenase (EC 1.2.99.2).
[0379] The nucleotide sequences of suitable genes for the enzymes E63 to E67 can be found in the KEGG database, the NCBI database or the EMBL database.
[0380] According to a third special embodiment of the cell according to the invention, where the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via methylmalonate-semialdehyde as precursor, it is preferred that the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoate based on 3-hydroxyisobutyric acid takes place via acryloyl-coenzyme A as intermediate, where the cell is capable of preferentially utilizing carbohydrates, glycerol or glutamate as carbon source.
[0381] In connection with the third special embodiment of the cell according to the invention, it is especially preferred when this cell features an activity of at least one of the following enzymes E10 to E12, E56, E72 and E73 which is increased in comparison with its wild type (see FIG. 15):
[0382] of an enzyme E72, which catalyzes the conversion of beta-alanine to beta-alanyl-coenzyme A,
[0383] of an enzyme E73, which catalyzes the conversion of beta-alanyl-coenzyme A into acrylyl-coenzyme A,
[0384] of an enzyme E56, which catalyzes the conversion of acrylyl-coenzyme A into methylmalonyl-coenzyme A,
[0385] of an enzyme E10, which catalyzes the conversion of methylmalonyl-coenzyme A into methyl malonate;
[0386] of an enzyme E11, which catalyzes the conversion of methyl malonate into methylmalonate-semialdehyde;
[0387] of an enzyme E12, which catalyzes the conversion of methylmalonate-semialdehyde into 3-hydroxyisobutyric acid.
[0388] In this context, cells which are especially preferred according to the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E56E10, E56E11, E56E12, E56E10E11 and E72E73E56E10E11E12. In connection with the fourth special embodiment, too, of the cell according to the invention it may be advantageous to overexpress an enzyme which is capable of catalyzing at least two of the above-described reaction steps. Here too, it is possible for example to employ an enzyme which features both the activity of the enzyme E10 and the activity of the enzyme E11, such as, for example, the malonyl-coenzyme A reductase from Sulfolobus tokodaii, which is encoded by the DNA sequence with the SEQ ID No 03 and which features the amino acid sequence as shown in SEQ ID No 04. Furthermore, it is, in principle, also possible in the context of the fourth special embodiment of the cell according to the invention to employ a cell which is already capable of forming especially large amounts of acrylyl-coenzyme A.
[0389] In this context, it is especially preferred that the enzyme
[0390] E72 is a coenzyme A transferase (EC 2.8.3.1) or a coenzyme A synthetase, preferably a coenzyme A transferase,
[0391] E73 is a beta-alanyl-coenzyme A ammonia-lyase (EC 4.3.1.6),
[0392] E56 is a crotonyl-coenzyme A decarboxylase
[0393] E10 is a methylmalonyl-coenzyme A hydrolase (EC 3.1.2.17),
[0394] E11 is an aldehyde dehydrogenase (EC 1.2.1.3) or an aldehyde oxidase (EC 1.2.3.1) and
[0395] E12 is a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) or a 3-hydroxyacyl-coenzyme A dehydrogenase (EC 1.1.1.35).
[0396] Preferred enzymes E72 with a CoA transferase activity are those from Megasphaera elsdenii, Clostridium propionicum, Clostridium kluyveri and also from Escherichia coli. Examples which may be mentioned at this point of a DNA sequence coding for a CoA transferase is the sequence from Megasphaera elsdenii referred to as SEQ ID No: 24 in WO-A-03/062173. Enzymes which are furthermore preferred are those variants of the CoA transferase which are described in WO-A-03/062173.
[0397] Suitable enzymes E73 with a beta-alanyl-coenzyme A ammonia-lyase activity are, for example, those from Clostridium propionicum. DNA sequences which code for such an enzyme can be obtained for example from Clostridium propionicum as described in Example 10 in WO-A-03/062173. The DNA sequence which codes for the beta-alanyl-coenzyme A ammonia-lyase from Clostridium propionicum is specified in WO-A-03/062173 as SEQ ID No: 22.
[0398] An enzyme E56 which is preferably employed is, again, the crotonyl-coenzyme A decarboxylase from Rhodobacter sphaeroides, which is encoded by the DNA sequence with the SEQ ID No 05 and which features the amino acid sequence as shown in SEQ ID No 06. This enzyme is not only capable of converting crotonyl-coenzyme A into ethylmalonyl-coenzyme A, but also of converting acrylyl-coenzyme A into methylmalonyl-coenzyme A.
[0399] Suitable genes for the enzymes E10 to E12 have already been mentioned in connection with the first variant of the cell according to the invention, where it is also preferred in connection with the second variant, the above-described gene from Sulfolobus tokodaii is especially preferred as gene for the enzyme E11.
[0400] According to an especially preferred variant of the third special embodiment of the cell according to the invention, this cell features at least one activity of the enzyme E10 and E56 or of the enzymes E10, E11 and E56 which is increased in comparison with its wild type, where the E10 or the enzymes E10 and E11 is encoded by a DNA sequence as shown in SEQ ID No 03 and the enzyme E56 is encoded by a DNA sequence as shown in SEQ ID No 05. In this context, it is preferred when the increased activity of these two enzymes is achieved by overexpressing, in the cell, the polypeptides with SEQ ID No 04 and SEQ ID No 06 or else that amino acid sequences with at least 50%, preferably at least 55%, more preferably at least 60%, more preferably at least 65% and most preferably at least 70% identity with the amino acid sequence as shown in SEQ ID No 04 and SEQ ID No 06, respectively. In this context, these two DNA sequences may be integrated into the genome of the cell or else be present on a vector inside the cell.
[0401] In connection with the above-described third special embodiment of the cell according to the invention, it may furthermore be advantageous when the cell features not only an increase in the activity of the enzyme E56 and/or of the activity of the enzyme E10 or of the enzymes E10 and E11, but at least one, preferably both, of the following properties:
[0402] an activity of an enzyme E11, which catalyzes the conversion of pyruvate into oxaloacetate or of an enzyme E74, which catalyzes the conversion of phosphoenolpyruvate into oxaloacetate, but preferably of an enzyme E11, which catalyzes the conversion of pyruvate into oxaloacetate, which is increased in comparison with its wild type, and
[0403] an increased activity of an enzyme E75, which catalyzes the conversion of aspartate into beta-alanine.
[0404] The enzyme E11 preferably takes the form of a carboxylase, especially preferably of a pyruvate carboxylase (EC number 6.4.1.1), which catalyzes the conversion of pyruvate into oxaloacetate. A pyruvate carboxylase which is especially preferred in this context is the mutant which is described in "A novel methodology employing Corynebacterium glutamicum genome information to generate a new L-lysine-producing mutant." Ohnishi J et al., Applied Microbiology and Biotechnology, Vol. 58 (2), pages 217-223 (2002). In this mutation, the amino acid proline at position 458 has been substituted by serine. The disclosure of this publication with regard to the possibilities of preparing pyruvate carboxylate mutants is hereby incorporated by referent and forms part of the disclosure of the present invention.
[0405] The enzyme E75 preferably takes the form of a decarboxylase, especially preferably of a glutamate decarboxylate or of an aspartate decarboxylase, with a 1-aspartate 1-decarboxylase (EC number 4.1.1.11) which is encoded by the panD gene being most preferred. Aspartate decarboxylase catalyzes the conversion of aspartate into beta-alanine. Genes for aspartate decarboxylase (panD genes) from, inter alia, Escherichia coli (FEMS Microbiology Letters, 143, pages 247-252 (1996)), "Photorhabdus luminescens subsp. Laumondii, Mycobacterium bovis subsp. Bovis") and from a large number of other microorganisms have already been cloned and sequenced. DE-A-198 55 313 describes in particular the nucleotide sequence of the panD gene from Corynebacterium glutamicum. In principle, it is possible to use panD genes of any feasible origin, no matter whether from bacteria, yeasts or fungi. Furthermore, it is possible to employ all alleles of the panD gene, in particular also those which are the result of the degeneracy of the genetic code or of function-neutral sense mutations. An aspartate decarboxylase which is especially preferred according to the invention, besides the aspartate decarboxylase from Corynebacterium glutamicum, is the Escherichia coli mutant DV9 (Vallari and Rock, Journal of Bacteriology, 164, pages 136-142 (1985)). The disclosure of this publication with regard to the abovementioned mutant is hereby incorporated by reference and forms part of the disclosure of the present invention. The preparation of recombinant cells in which both the activity of the pyruvate carboxylase and the activity of the aspartate decarboxylase is increased is described in DE-A-10 2005 048 818.
[0406] According to a second variant of the cell according to the invention, the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor.
[0407] In the event that, in the cell according to the invention, the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor, as specified in the second variant, it is preferred according to a first special embodiment that the formation of 3-hydroxyisobutyric acid or of the polyhydroxyalkanoate based on 3-hydroxyisobutyric acid takes place via isobutyryl-coenzyme A as intermediate, where the cell is capable of preferentially utilizing carbohydrates, glycerol or L-valine as carbon source.
[0408] In the event that carbohydrates or glycerol act as the carbon source, it is preferred, according to a first alternative of this first special embodiment of the second variant of the cell according to the invention that this cell features an activity of at least one of the following enzymes E76 to E79, E60, E61 and E8 which is increased in comparison with its wild type (see FIG. 16):
[0409] of an enzyme E76, which catalyzes the conversion of pyruvate into 2-acetolactate;
[0410] of an enzyme E77, which catalyzes the conversion of 2-acetolactate into 2,3-dihydroxyisovalerate;
[0411] of an enzyme E78, which catalyzes the conversion of 2,3-dihydroxyisovalerate into 2-oxoisovalerate;
[0412] of an enzyme E79, which catalyzes the conversion of 2-oxoisovalerate into isobutyryl-coenzyme A;
[0413] of an enzyme E60, which catalyzes the conversion of isobutyryl-coenzyme A into methacrylyl-coenzyme A;
[0414] of an enzyme E61, which catalyzes the conversion of methacrylyl-coenzyme A into 3-hydroxyisobutyryl-coenzyme A;
[0415] of an enzyme E8, which catalyzes the conversion of 3-hydroxyisobutyryl-coenzyme A into 3-hydroxyisobutyrate.
[0416] In this context, genetically modified cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E8, E60, E61, E76, E77, E78, E79 and E8E60E61E76E77E78E79.
[0417] In this context, it is especially preferred that the enzyme
[0418] E8 is a 3-hydroxyisobutyryl-coenzyme A hydrolase (EC 3.1.2.4),
[0419] E76 is an acetolactate synthase (EC 2.2.1.6),
[0420] E77 is a dihydroxyisovalerate dehydrogenase (EC 1.1.1.86),
[0421] E78 is a 2,3-dihydroxyisovalerate dehydratase (EC 4.2.1.9),
[0422] E79 is a 2-oxoisovalerate dehydrogenase (EC 1.2.1.25 or EC 1.2.4.4),
[0423] E60 is an acyl-coenzyme A dehydrogenase (EC 1.3.99.3), a butyryl-coenzyme A dehydrogenase (EC 1.3.99.2) or a 2-methylacyl-coenzyme A dehydrogenase (EC 1.3.99.12), and
[0424] E61 is an enoyl-coenzyme A hydratase (EC 4.2.1.17).
[0425] Preferred enzymes E8, E60 and E61 are those which have already been described above.
[0426] The enzyme E76 is preferably encoded by genes selected from the group consisting of ilvb1, t8p19.70, ilv1, ilv2, ilv6, aa1021wp, ae1305cp, ilvI, ilvH, ilvN, ilvB, ilvM, ilvG, ilvN, budB, ilvN-1, ilvN-2, atrC, ilvX, iolD, budB, alsS, ilvK, ilvB1, ilvB2, ilvB3, ilvN1, ilvN2, cgl1271, cgl1272, iolD and scc57A.40c.
[0427] The enzyme E77 is preferably encoded by genes selected from the group consisting of f14p22.200, ilv5, ac1198Wp, ilvC, ilvY, ilvC-1, ilvC-2, ilvC-3 and cgl1273, where the ilvC gene is most preferred.
[0428] The enzyme E78 is preferably encoded by genes selected from the group consisting of f14o13.18, ilv3, acl117wp, ilvD, cgl1268, ilvD1 and ilvD2, where ilvD is most preferred.
[0429] In the event that L-valine acts as carbon source, it is preferred according to a second modification of the first special embodiment of the second alternative of the cell according to the invention, where the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor and isobutyryl-coenzyme A as intermediate, that this cell features an activity of at least one of the following enzymes E79, E80, E60, E61 and E8 which is increased in comparison with its wild type (see FIG. 17):
[0430] of an enzyme E80, which catalyzes the conversion of L-valine into 2-oxoisovalerate;
[0431] of an enzyme E79, which catalyzes the conversion of 2-oxoisovalerate into isobutyryl-coenzyme A;
[0432] of an enzyme E60, which catalyzes the conversion of isobutyryl-coenzyme A into methacrylyl-coenzyme A;
[0433] of an enzyme E61, which catalyzes the conversion of methacrylyl-coenzyme A into 3-hydroxyisobutyryl-coenzyme A;
[0434] of an enzyme E8, which catalyzes the conversion of 3-hydroxyisobutyryl-coenzyme A into 3-hydroxyisobutyrate.
[0435] In this context, genetically modified cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E8, E60, E61, E79, E80 and E8E60E61E79E80.
[0436] In this context, it is especially preferred that the enzyme
[0437] E8 is a 3-hydroxyisobutyryl-coenzyme A hydrolase (EC 3.1.2.4),
[0438] E60 is an acyl-coenzyme A dehydrogenase (EC 1.3.99.3), a butyryl-coenzyme A dehydrogenase (EC 1.3.99.2) or a 2-methylacyl-coenzyme A dehydrogenase (EC 1.3.99.12),
[0439] E61 is an enoyl-coenzyme A hydratase (EC 4.2.1.17),
[0440] E79 is a 2-oxoisovalerate dehydrogenase (EC 1.2.1.25 or EC 1.2.4.4), and
[0441] E80 is an amino acid transferase (EC 2.6.1.42),
[0442] Preferred enzymes E8, E60, E61 and E79 are those which have already been described above.
[0443] The enzyme E80 is preferably encoded by genes selected from the group consisting of bcat1, bcat2, t27I1.8, t27i1.9, f2j10.5, f2j10.4, t12h1.16, mmb12.20, t9c5.3, mpa24.13, bat1, bat2, ad1384wp, eca39, bcaA, ilvE, ilvE1, ilvE2, ilvE3, ywaA, ybgE, bcaT and cgl2204, where ilvE is especially preferred.
[0444] The nucleotide sequences of suitable genes the enzyme E80 can, again, be found in the KEGG database, the NCBI database or the EMBL database.
[0445] In connection with this second alternative of the first special embodiment of the second variant of the cell according to the invention, it may furthermore be advantageous to reduce the activity of an enzyme E4 which catalyzes the conversion of methylmalonate-semialdehyde into 3-hydroxyisobutyric acid, where this enzyme E4 preferably takes the form of a 3-hydroxyisobutyrate dehydrogenase (EC 1.1.1.31) or of a 3-hydroxy-acyl-coenzyme A dehydrogenase (EC 1.1.1.35).
[0446] According to the second modification of the first special embodiment of the second variant of the cell according to the invention, where the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor and isobutyryl-coenzyme A as intermediate and starting from L-valine as carbon source, it may furthermore be preferred to employ those cells which are already capable of forming large amounts of L-valine. In this context, suitable cells are in particular those which have been described by Blombach et al. in Applied Environmental Microbiology, Vol. 73 (7) (2007), pages 2079-2084.
[0447] In the event that C1-compounds such as, for example, methane or methanol act as carbon source, it is preferred in a second special embodiment of the second variant of the cell according to the invention, where the formation of 3-hydroxyisobutyric acid or of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid takes place via 3-hydroxyisobutyryl-coenzyme A as precursor, that the formation takes place via 3-hydroxyisobutyryl-coenzyme A as intermediate. In this context, it is preferred that the cell features an activity of at least one of the following enzymes E8, E53, E54 and E81 which is increased in comparison with its wild type:
[0448] of an enzyme E53, which catalyzes the conversion of acetyl-coenzyme A into acetoacetyl-coenzyme A;
[0449] of an enzyme E54, which catalyzes the conversion of acetoacetyl-coenzyme A into 3-hydroxybutyryl-coenzyme A;
[0450] of an enzyme E81, which catalyzes the conversion of 3-hydroxybutyryl-coenzyme A into 3-hydroxy-isobutyryl-coenzyme A;
[0451] of an enzyme E8, which catalyzes the conversion of 3-hydroxyisobutyryl-coenzyme A into 3-hydroxyisobutyrate.
[0452] In this context, genetically modified cells which are especially preferred in accordance with the invention are those in which the activity of the following enzymes or enzyme combinations is increased: E8, E53, E54, E81 and E8E53E54E81.
[0453] In this context, it is especially preferred that the enzyme
[0454] E8 is a 3-hydroxyisobutyryl-coenzyme A hydrolase (EC 3.1.2.4),
[0455] E53 is a β-ketothiolase (EC 2.3.1.9),
[0456] E54 is an acetoacetyl-coenzyme A reductase (an EC 1.1.1.36), and
[0457] E81 is an isobutyryl-coenzyme mutase (EC 5.4.99.13).
[0458] Preferred enzymes E8, E53 and E54 are those which have already been described hereinabove. A preferred enzyme E81 is the isobutyryl-coenzyme mutase from β-proteo-bacterium strain L108 which is described in Applied And Environmental Microbiology, Vol. 72 (6), 2006, pages 4128-4135.
[0459] According to a special embodiment of the cell according to the invention, it is furthermore preferred that this cell features an expression of the glb0 gene which is increased in comparison with its wild type. Furthermore, it may under certain circumstances be preferred that the cell according to the invention features an activity of the citrate transport protein which is encoded by the dctA gene or the citP gene, which activity is reduced in comparison with its wild type.
[0460] A contribution to the solution of the problems mentioned at the outset is furthermore provided by a method of preparing a genetically modified cell which is capable of forming 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid via methylmalonate-semialdehyde or isobutyryl-coenzyme A, as precursors, comprising the method step of increasing, in the cell, the activity of at least one of the above-described enzymes, preferably of one or more of the enzymes
[0461] E1 to E4,
[0462] E1, E4, E5, E6 and E7,
[0463] E1, E4, E5 and E7,
[0464] E4, E5 and E47 to E52,
[0465] E2 to E4, E6, E7 and E47 to E52,
[0466] E2 to E4, E7 and E47 to E52,
[0467] E8 and E53 to E61,
[0468] E8, E60, E61 and E76 to E79,
[0469] E8, E60, E61, E79 and E80, or
[0470] E8, E53, E54 and E82 in the cell, where increasing the enzymatic activity is preferably carried out by the methods described at the outset.
[0471] Another contribution to the solution of the problems mentioned at the outset is provided by the cells obtainable by the above-described method.
[0472] Another contribution to the solution of the problems mentioned at the outset is provided by a method of producing 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid, comprising the method step of bringing a cell according to the invention into contact with a nutrient medium comprising, as carbon source, carbohydrates, glycerol, carbon dioxide, methane, methanol, L-valine or L-glutamate under conditions under which 3-hydroxyisobutyric acid or polyhydroxyalkanoates based on 3-hydroxyisobutyric acid are formed from the carbon source, and, if appropriate, isolation of the 3-hydroxyisobutyric acid from the nutrient medium.
[0473] The genetically modified cells according to the invention can be into contact with the nutrient medium, and thus cultured, either continuously or batchwise in the batch method or in the fed-batch method or in the repeated-fed-batch method in order to produce 3-hydroxyisobutyrate or polyhydroxyalkanoates based on 3-hydroxyisobutyrate. A semicontinuous method as described in GB-A-1009370 is also feasible. An overview over known culture methods are described in the textbook by Chmiel ("Bioprozesstechnik 1. Einfuhrung in die Bioverfahrenstechnik" [Bioprocess technology 1. introduction to bioprocess technology] (Gustav Fischer Verlag, Stuttgart, 1991)) or in the textbook by Storhas ("Bioreaktoren und periphere Einrichtungen", [Bioreactors and peripheral equipment] Vieweg Verlag, Braunschweig/Wiesbaden, 1994).
[0474] The culture medium to be used must suitably meet the requirements of the strains in question. Descriptions of culture media for various microorganisms can be found in the textbook "Manual of Methods for General Bacteriology" of the American Society for Bacteriology (Washington D.C., USA, 1981).
[0475] Carbon sources which may be used are carbohydrates such as, for example, glucose, sucrose, lactose, fructose, maltose, molasses, starch and cellulose, oils and fats such as, for example, soy oil, sunflower oil, peanut oil and coconut fat, fatty acids such as, for example, palmitic acid, stearic acid and linolic acid, alcohols such as, for example, glycerol and methanol, hydrocarbons such as methane, amino acids such as L-glutamate or L-valine, or organic acids such as, for example, acetic acid. These substances may be used singularly or as a mixture. It is especially preferred to employ carbohydrates, in particular monosaccharides, oligosaccharides or polysaccharides, as described in U.S. Pat. No. 601,494 and U.S. Pat. No. 6,136,576, or C5-sugars, or glycerol.
[0476] Nitrogen sources which can be used are organic nitrogen-comprising compounds such as peptones, yeast extract, meat extract, malt extract, cornsteep liquor, soya mill and urea, or inorganic compounds such as ammonium sulfate, ammonium chloride, ammonium phosphate, ammonium carbonate and ammonium nitrate. The nitrogen sources can be used singularly or as a mixture.
[0477] Phosphoric acid, potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding sodium-comprising salts can be used as sources of phosphorus. The culture medium must furthermore comprise salts of metals such as, for example, magnesium sulfate or iron sulfate, which are required for growth. Finally, essential growth factors such as amino acids and vitamins may be employed in addition to the abovementioned substances. Moreover, suitable precursors may be added to the culture medium. The abovementioned input materials may be added to the culture in the form of a single batch or else fed in a suitable manner during culturing.
[0478] The pH for the culture can be controlled by employing, in an appropriate manner, basic compounds such as sodium hydroxide, potassium hydroxide, ammonia and aqueous ammonia, or acidic compounds such as phosphoric acid or sulfuric acid. Foaming can be controlled by employing antifoams such as, for example, fatty acid polyglycol esters. To maintain the stability of plasmids, it is possible to add to the medium suitable substances which have a selective effect, such as, for example, antibiotics. Aerobic conditions are maintained by introducing, into the culture, oxygen or oxygen-containing gas mixtures such as, for example, ambient air. The culture temperature is normally 20° C. to 45° C. and preferably 25° C. to 40° C. It may be preferred to employ, as cells, those cells which are described in U.S. Pat. No. 6,803,218, in particular when using cells which are capable of converting glycerol as the substrate. In this case, the cells can be cultured at temperatures in the range of from 40 to 100° C.
[0479] The isolation of 3-hydroxyisobutyric acid from the nutrient solution is preferably carried out continuously, it being furthermore preferred in this context also to produce 3-hydroxyisobutyric acid by fermentation in a continuous manner, so that the entire process from the production of 3-hydroxyisobutyric acid up to its isolation from the fermentation liquor can be carried out continuously. For the continuous isolation of the production of 3-hydroxyisobutyric acid from the fermentation liquor, the former is continuously passed over a device for removing the microorganisms employed during fermentation, preferably through a filter with an exclusion level in the range of from 20 to 200 kDa, where a solid/liquid separation takes place. It is also feasible to employ a centrifuge, a suitable sedimentation device or a combination of these devices, it being especially preferred to first separate at least part of the microorganisms by sedimentation and subsequently to feed the fermentation liquor, which has been freed from part of the microorganisms, to ultrafiltration or to a centrifugation device.
[0480] After the microorganisms have been removed, the fermentation product, which is enriched with regard to its 3-hydroxyisobutyric acid fraction, is fed to a separation system, preferably a multistep separation system. This separation system provides a plurality of separation steps which are connected in series, from which steps in each case return lines lead away and back to the fermentation tank. Furthermore, exit pipes lead out of the respective separation steps. The individual separation steps may operate by the electrodialysis, the reverse osmosis, the ultrafiltration or the nanofiltration principle. As a rule, these are membrane separation devices in the individual separation steps. The selection of the individual separation steps is a function of the nature and the extent of the fermentation by-products and substrate residues.
[0481] Besides the 3-hydroxyisobutyric acid being separated off by means of electrodialysis, reverse osmosis, ultrafiltration or nanofiltration, in the course of which an aqueous 3-hydroxyisobutyric acid solution is obtained as the end product, the 3-hydroxyisobutyric acid can also be separated off by extractive methods from the fermentation solution which has been freed from microorganisms, in which case, finally, the pure 3-hydroxyisobutyric acid can be obtained. To separate the 3-hydroxyisobutryic acid by extraction, it is possible to add, to the fermentation solution, for example ammonium compounds or amines in order to form an ammonium salt of 3-hydroxyisobutyric acid. This ammonium salt can then be separated from the fermentation solution by adding an organic extractant and subsequently heating the resulting mixture, whereby the ammonium salt is concentrated in the organic phase. Then, the 3-hydroxyisobutyric acid can be isolated from this phase for example by further extraction steps, giving the pure 3-hydroxyisobutyric acid. More details regarding the separation method can be found in WO-A-02/090312, whose disclosure regarding the separation of hydroxycarboxylic acids from fermentation solutions is hereby incorporated by reference and forms part of the disclosure of the present application.
[0482] Depending on the way in which the 3-hydroxyisobutyric acid is separated from the fermentation solution, either an aqueous solution of 3-hydroxyisobutyric acid comprising 2 to 90% by weight, preferably 7.5 to 50% by weight and especially preferably 10 to 25% by weight of 3-hydroxyisobutyric acid, or else pure 3-hydroxyisobutyric acid is obtained.
[0483] Furthermore, the 3-hydroxyisobutyric acid prepared by the method according to the invention can also be neutralized, either before, during or after the purification, for which purpose bases such as, for example, calcium hydroxide or sodium hydroxide can be employed.
[0484] A contribution to solving the problems mentioned at the outset is provided in particular also by a method of preparing methacrylic acid or methacrylic esters, comprising the method steps
[0485] IA) preparation of 3-hydroxyisobutyric acid by the method described above and, if appropriate, isolation and/or neutralization of the 3-hydroxyisobutyric acid of the 3-hydroxyisobutyric acid,
[0486] IB) dehydration of the 3-hydroxyisobutyric acid with formation of methacrylic acid and, if appropriate, esterification of the methacrylate or of the methacrylic acid.
[0487] According to method step IB), the 3-hydroxyisobutyric acid is dehydrated with formation of methacrylic acid, for which purpose it is possible either to employ the pure 3-hydroxyisobutyric acid isolated from the fermentation solution or else the aqueous solution of 3-hydroxyisobutryic acid, which has been isolated when working up the fermentation solution, it also being possible to concentrate the aqueous solution of 3-hydroxyisobutyric acid, if appropriate, before the dehydration step, for example by means of distillation, if appropriate in the presence of a suitable entrainer.
[0488] The dehydration reaction can, in principle, be carried out in liquid phase or in the gas phase. Furthermore, it is preferred in accordance with the invention that the dehydration reaction is carried out in the presence of a catalyst, with the nature of the catalyst employed depending on whether a gas-phase or a liquid-phase reaction is carried out.
[0489] Suitable dehydration catalysts are both acidic catalysts and alkaline catalysts. Acidic catalysts are preferred, in particular because they show less tendency to form oligomers. The dehydration catalyst may be employed both as a homogeneous and as a heterogeneous catalyst. If the dehydration catalyst is present in the form of a heterogeneous catalyst, it is preferred that the dehydration catalyst is in contact with a support x. Suitable supports x are all solids believed by the skilled worker to be suitable. In the present context, it is preferred that the solids have suitable pore volumes which are suitable for good binding and absorption of the dehydration catalyst. Furthermore, total pore volumes as specified by DIN 66133 in a range of from 0.01 to 3 ml/g are preferred, and total pore volumes in the range of from 0.1 to 1.5 ml/g are especially preferred. Moreover, it is preferred that the solids which are suitable as support x have a surface area in the range of from 0.001 to 1000 m2/g, preferably in the range of from 0.005 to 450 m2/g and furthermore preferred in the range of from 0.01 to 300 m2/g as determined by BET test as specified in DIN 66131. A support which may be employed for the dehydration catalyst can firstly be bulk material with a mean particle diameter in the range of from 0.1 to 40 mm, preferably in the range of from 1 to 10 mm, and furthermore preferably in the range from 1.5 to 5 mm. The wall of the dehydration reactor may furthermore act as support. Furthermore, the support may be acidic or alkaline per se, or else an acidic or alkaline dehydration catalyst may be applied to an inert support. Application techniques which may be mentioned in particular are immersion or impregnation or else incorporation into a support matrix.
[0490] Suitable supports x, which may also feature dehydration catalyst properties, are, in particular, natural or synthetic silicates such as, in particular, mordenite, montmorillonite, acidic zeolites; supports which are coated with monobasic, dibasic or polybasic inorganic acids, in particular phosphoric acid, or with acidic salts of inorganic acids, such as substances of the oxide or silicate type, for example Al2O3, TiO2; oxides and mixed oxides such as, for example, γ-Al2O3 and ZnO--Al2O3 mixed oxides of the heteropolyacids.
[0491] In accordance with an embodiment according to the invention, the support x consists at least in part of a compound of the oxide type. Such compounds of the oxide type should feature at least one of the elements selected from among Si, Ti, Zr, Al, P or a combination of at least two of these. Such supports may also act as dehydration catalyst themselves, owing to their acidic or alkaline properties. A preferred class of compounds, both as support by way of x and by way of dehydration catalyst comprise silicon/aluminum/phosphorus oxides. Preferred alkaline substances which act both as dehydration catalyst and also as support x comprise alkali, alkaline earth, lanthanum, lanthoids or a combination of at least two of these in the form of their oxides. Such acidic or alkaline dehydration catalysts are commercially available both from Degussa AG and from Sudchemie AG. A further class are ion exchangers. Again, these may be present both in alkaline and in acidic form.
[0492] Suitable homogeneous dehydration catalysts are, in particular, inorganic acids, preferably phosphorus-containing acids and furthermore preferably phosphoric acid. These inorganic acids can be immobilized on the support x by immersion or impregnation.
[0493] The use of heterogeneous catalysts has proved particularly advantageous in particular in the case of gas phase dehydration. In the case of liquid-phase dehydration, however, both homogeneous and heterogeneous dehydration catalysts are employed.
[0494] Furthermore, it is preferred that the method according to the invention involves the use of a dehydration catalyst with an H0 value in the range of from +1 to -10, preferably in the range of from +2 to -8.2 and furthermore preferably, in the case of liquid-phase dehydration, in the range of from +2 to -3 and in gas-phase dehydration in the range of from -3 to -8.2. The H0 value corresponds to the acid function as defined by Hammert and can be determined by what is known as amine titration and the use of indicators, or by the absorption of a gaseous base (see "Studies in Surface Science and Catalytics", vol. 51, 1989: "New solid Acids and Bases, their catalytic Properties", K. Tannabe et al).
[0495] According to a special embodiment of the method according to the invention, the acidic solid catalyst employed is a porous support structure which has been brought into contact with an inorganic acid, preferably with phosphoric acid or with superacids such as, for example, sulfated or phosphated zirconium oxide and which is based preferably on at least 90% by weight, furthermore preferably at least 95% by weight and most preferably at least 99% by weight of a silicon oxide, preferably an SiO2. The bringing into contact of the porous support structure with the inorganic acid is preferably carried out by impregnating the support structure with the acid, with the latter preferably being brought into contact with the former in an amount in a range of from 10 to 70% by weight, especially preferably in the range of from 20 to 60% by weight and more preferably in a range of from 30 to 50% by weight, based on the weight of the support structure, followed by drying. After drying, the support structure is heated in order to fix the inorganic acid, preferably at a temperature in a range of from 300 to 600° C., more preferably in a range of from 400 to 500° C.
[0496] According to a special embodiment of the method according to the invention, the dehydration reaction is carried out in the gas phase. Here, it is possible to employ conventional apparatuses as are known to the skilled worker in the field of gas phase reaction, for example tubular reactors. It is especially preferred to employ shell-and-tube heat exchangers and reactors which comprise thermoplates as heat exchangers.
[0497] According to an embodiment of the gas-phase dehydration reaction, pure 3-hydroxyisobutyric acid is introduced into a reactor comprising one of the abovementioned fixed-bed catalysts. According to another embodiment, the 3-hydroxyisobutyric acid is introduced into the reactor in the form of an aqueous solution comprising 2 to 80% by weight, especially preferably 5 to 50% by weight and more preferably 10 to 25% by weight of 3-hydroxyisobutyric acid, in each case based on the total weight of the aqueous solution. The pressure and temperature conditions inside the reactor are chosen such that the 3-hydroxyisobutyric acid, or the aqueous solution, is present in gaseous form when entering the reactor. The dehydration in the gas phase is preferably carried out in the temperature range of between 200 and 400° C., especially preferably between 250 and 350° C. The pressure inside the reactor during the gas-phase dehydration reaction is preferably in a range of from 0.1 to 50 bar, especially preferably in a range of from 0.2 to 10 bar and most preferably in a range of from 0.5 to 5 bar.
[0498] The amount of 3-hydroxyisobutyric acid introduced into the reactor in the gas-phase dehydration reaction is preferably in a range of from 10 to 100% by volume, especially preferably in a range of from 20 to 100% by volume and most preferably in a range of from 30 to 100% by volume.
[0499] According to another special embodiment of the method according to the invention, the dehydration reaction is performed in the liquid phase. The liquid-phase dehydration reaction can also be carried out in all apparatuses which are known to the skilled worker and in which a fluid can be heated to a desired reaction temperature, during which process a pressure can be applied to the apparatus which is sufficient for maintaining the reaction components in the liquid state under the desired temperature conditions.
[0500] According to a special embodiment of the method according to the invention, the liquid-phase dehydration method comprises a first method step, in which pure 3-hydroxyisobutyric acid or an aqueous solution comprising 5 to 100% by weight, especially preferably 20 to 100% by weight and most preferably 50 to 100% by weight of 3-hydroxyisobutyric acid, based on the total weight of the aqueous solution, is introduced into a reactor. The pressure and temperature conditions inside the reactor are chosen such that the 3-hydroxyisobutyric acid, or the aqueous solution, is present in liquid form when entering the reactor. According to a special embodiment of the method according to the invention in which the dehydration reaction is carried out in the liquid phase, the 3-hydroxyisobutyric acid, or the aqueous solution, is passed in such a way over a fixed catalyst bed inside the dehydration reactor that the liquid phase trickles over the surface of the catalyst particles. Such a procedure may be carried out for example in a trickle-bed reactor.
[0501] The dehydration in the liquid phase is preferably carried out in a temperature range of between 200 and 350° C., especially preferably between 250 and 300° C. The pressure inside the reactor in the case of liquid-phase dehydration is preferably in a range of from 1 to 50 bar, especially preferably in a range of from 2 to 25 bar and most preferably in a range of from 3 to 10 bar.
[0502] The catalysis of the dehydration reaction may be homogeneous or heterogeneous, both in the case of gas-phase dehydration and in the case of liquid-phase dehydration.
[0503] In the case of homogeneous catalysis, the catalyst, which in this case preferably takes the form of an inorganic acid such as, for example, phosphoric acid or sulfuric acid, is first brought into contact with the pure 3-hydroxyisobutyric acid or with the aqueous solution comprising the 3-hydroxyisobutyric acid. Thereafter, the resulting composition is introduced into the reactor and converted into methacrylic acid under the desired pressure and temperature conditions. It is also feasible to introduce the inorganic acid independently of the 3-hydroxyisobutyric acid or the aqueous solution into the reactor. In this case, the reactor features at least two feed lines, one for the 3-hydroxyisobutyric acid, or the aqueous solution comprising 3-hydroxyisobutyric acid, and one for the catalyst. If the dehydration reaction is carried out in liquid phase in a trickle-bed reactor, it is preferred to introduce the catalyst together with the 3-hydroxyisobutyric acid, or the aqueous solution comprising the 3-hydroxyisobutyric acid, at the top of the reactor.
[0504] In the case of heterogeneous catalysis, the catalyst is in the form of a solid substrate located in the reaction space, for example in the form of a fixed bed, in the form of catalyst-coated plates, preferably thermoplates, which are arranged inside the reactor, or else in the form of catalyst-coated reactor walls. Reactors which are possible are described for example in DE-A-198 48 208, DE-A-100 19 381 and EP-A-I 234 612. In the case of heterogeneous catalysis, preferred catalysts are support structures which have been brought into contact with inorganic acids, preferably impregnated porous support structures. The 3-hydroxyisobutyric acid, or the aqueous solution comprising the 3-hydroxyisobutyric acid, is then brought into contact with the surface of the solid catalyst material in the form of a vapor, or in liquid form.
[0505] According to an especially preferred embodiment of the method according to the invention, the dehydration of the 3-hydroxyisobutyric acid is carried out in liquid phase at a pressure in the range of from 200 to 500 mbar, at a temperature in a range of from 200 to 230° C. and in the presence of alkali metal ions as the catalyst.
[0506] The reaction mixture which is obtained after the dehydration reaction is either an aqueous methacrylic acid solution which does not contain any catalyst components (such a solution is obtained in the case of heterogeneously catalyzed dehydration) or else an aqueous methacrylic acid solution which comprises catalysts (such a solution is obtained in the case of homogeneously catalyzed dehydration). Furthermore, the aqueous methacrylic acid solution may be in liquid form (if the dehydration reaction has been effected in the liquid phase) or in gaseous form (if the dehydration reaction has been carried out in the gas phase).
[0507] If appropriate, the resulting methacrylic acid solution can, according to a special embodiment of the method according to the invention, be esterified without further processing. In such a case, the methacrylic acid solution is brought into contact with suitable alcohols such as, for example, methanol, ethanol, 1-propanol, 2-propanol or 1-butanol and suitable esterification catalysts known to the skilled worker such as, for example, concentrated acids, with heating, and the methacrylic acid is so converted into the corresponding esters. However, it may be advantageous additionally to purify the methacrylic acid before esterification, it being possible to employ, in principle, any purification method which is known to the skilled worker and which is conventionally employed for the purification of contaminated (meth)acrylic acid obtained by catalytic gas-phase oxidation of propylene.
[0508] If the dehydration reaction has been carried out in the gas phase, it is preferred that the methacrylic acid is first condensed, generating an aqueous methacrylic acid solution. Here, any condensation method known to the skilled worker may be employed in principle, for example a fractional condensation as described in WO-A-2004/035514, WO-A-03/014172 or EP-A-EP 1 163 201 or by total condensation as described in EP-A-0 695 736. It is also feasible to add additional solvents, in particular water, during the condensation process in order to absorb the methacrylic acid as completely as possible.
[0509] The aqueous methacrylic acid solution obtained after condensation, or else the aqueous methacrylic acid solution obtained in the event of liquid-phase dehydration, can then be freed from water and other contaminants in further purification steps. Here, it is possible first to remove the water by azeotrope distillation in the presence of an entrainer as described, for example, in DE-A-198 53 064. It is also feasible to employ high-boiling organic solvents for absorbing the methacrylic acid, as is disclosed for example in EP-A-0 974 574. In addition to these distillation methods, membranes for dewatering may also be employed, as proposed for example in DE-A-44 01 405. Employing crystallization methods for purifying the aqueous methacrylic acid solution, which has been generated in the case of liquid-phase dehydration or which has been obtained by condensation, is furthermore feasible.
[0510] The methacrylic acid obtained after dehydration can be purified even further in further method steps. Thus, high-boiling contaminants which are still present can be removed by further distillation steps. However, it is especially preferred to further purify the methacrylic acid obtained by dehydration using crystallization methods as described for example in DE-A-101 49 353.
[0511] The resulting purified methacrylic acid can then be esterified, if appropriate.
[0512] A contribution to solving the problems mentioned at the outset is furthermore provided by a method of preparing methacrylic acid or methacrylic esters, comprising the method steps
[0513] IIA) preparation of polyhydroxyalkanoates based on 3-hydroxyisobutyric acid by the method described above,
[0514] IB) cleavage of the polyhydroxyalkanoates based on 3-hydroxyisobutyric acid with formation of 3-hydroxyisobutyric acid and, if appropriate, neutralization of the 3-hydroxyisobutyric acid and/or isolation of the 3-hydroxyisobutyric acid,
[0515] IIC) dehydration of the 3-hydroxyisobutyric acid with formation of methacrylic acid and, if appropriate, esterification of the methacrylate or methacrylic acid.
[0516] A contribution to solving the problems mentioned at the outset is also provided by a method of preparing polymethacrylic acid or polymethacrylic esters, comprising the method steps
[0517] IIIA) preparation of methacrylic acid by the method described above,
[0518] IIIB) free-radical polymerization of the methacrylic acid, it being possible, if appropriate, to esterify at least in part the carboxyl groups of the methacrylic acid before or after the free-radical polymerization reaction.
[0519] A contribution to solving the problem mentioned at the outset is furthermore provided by an isolated DNA, which is selected from the following sequences:
[0520] a) a sequence as shown in SEQ ID No 03,
[0521] b) an intron-free sequence which is derived from a sequence as specified in a) and which codes for the same protein or peptide as the sequence as shown in SEQ ID No 03,
[0522] c) a sequence which codes for a protein or peptide which comprises the amino acid sequence as shown in SEQ ID No 04,
[0523] d) a sequence with at least 80%, especially preferably at least 90%, more preferably at least 95% and most preferably 99% identity with a sequence as specified in one of groups a) to c), especially preferably as specified in group a), this sequence preferably coding for a protein or peptide which is capable of converting both S- or R-methylmalonyl-coenzyme A and malonyl-coenzyme A into the corresponding semialdehydes ((S)- or (R)-methylmalonate semialdehyde and malonate semialdehyde, respectively),
[0524] e) a sequence which hybridizes, or, taking into consideration the degeneration of the genetic code, would hybridize, with the counter strain of a sequence as specified in any of groups a) to d), especially preferably as specified in group a), this sequence preferably coding for a protein or peptide which is capable of converting both S- or R-methylmalonyl-coenzyme A and malonyl-coenzyme A into the corresponding semialdehydes ((S)- or (R)-methylmalonate semialdehyde and malonate semialdehyde, respectively),
[0525] f) a derivative of a sequence as specified in any of groups a) to e), especially preferably as specified in group a), this derivative preferably coding for a protein or peptide which is capable of converting both S- or R-methylmalonyl-coenzyme A and malonyl-coenzyme A into the corresponding semialdehydes ((S)- or (R)-methylmalonate semialdehyde and malonate semialdehyde, respectively), obtained by substitution, addition, inversion and/or deletion of at least one base, preferably of at least 2 bases, more preferably of at least 5 bases and most preferably at least 10 bases, but preferably of no more than 100 bases, especially preferably of no more than 50 bases and most preferably of no more than 25 bases, and
[0526] g) a sequence which is complementary to a sequence as specified in any of groups a) to f), especially preferably as specified in group a).
[0527] Surprisingly, it has been found that a DNA which has been isolated from bacteria of the strain Sulfolobus tokodaii (at the Deutsche Sammlung von Mikroorganismen [German collection of microorganisms], deposit number DSM 16993) and which has a DNA sequence as shown in SEQ ID No 03 codes for a polypeptide (SEQ ID No 04) which is capable even at temperatures of up to 75° C. of converting both S- or R-methylmalonyl-coenzyme A and malonyl-coenzyme A into the corresponding semialdehydes ((S)- or (R)-methylmalonate semialdehyde and malonate semialdehyde, respectively). Since (S)- or (R)-methylmalonate semialdehyde and malonate semialdehyde are natural metabolites which are formed for example during the degradation of valine, of leucin or of isoleucin, during the propanoate metabolism or during the pyruvate metabolism, and because the formed semialdehydes are capable of being reduced further in the course of the abovementioned metabolic pathways to give the corresponding 3-hydroxyalkanoates, the isolated DNA according to the invention can be utilized for generating recombinant bacteria which are capable of directly forming large amounts of 3-hydroxyisobutyric acid (or 3-hydroxypropionic acid). If the cells are furthermore capable of polymerizing the formed 3-hydroxyalkanoates with formation of polyhydroxyalkanoates, this DNA would furthermore be suitable for generating recombinant bacteria capable of producing polyhydroxyalkanoates based on 3-hydroxyisobuytric acid (or on 3-hydroxypropionic acid).
[0528] The "nucleotide identity" in relation to SEQ ID No 03, which is defined in alternative d), is determined with the aid of known methods here. In general, specialist computer programs with algorithms taking into consideration specific requirements are used.
[0529] Preferred methods of determining the identity first generate the maximum agreement between the sequences to be compared. Computer programs for determining the identity comprise the GCG program package, including but not limited thereto
[0530] GAP (Deveroy, J. et al., Nucleic Acid Research 12 (1984), page 387, Genetics Computer Group University of Wisconsin, Medicine (Wi)), and
[0531] BLASTP, BLASTN and FASTA (Altschul. S. et al., Journal of Molecular Biology 215 (1990), pages 403-410). The BLAST program may be obtained from the Center For Biotechnology Information (NCBI) and from other sources (BLAST Manual, Altschul S. et al., NCBI NLM NIH Bethesda ND 22894; Altschul S. et al., above).
[0532] The Smith-Waterman algorithm, which is known, can also be used for determining the nucleotide identity.
[0533] Preferred parameters for the nucleotide alignment comprise the following:
[0534] Algorithmus Needleman and Wunsch, Journal of Molecular Biology 48 (1970), pages 443-453
[0535] alignment matrix
TABLE-US-00001
[0535] Matches = +10 Mismatches = 0 Gap penalty = 50 Gap length penalty = 3
[0536] The GAP program is also suitable for use with the above parameters. The above parameters are the default parameters in the nucleotide sequence alignment.
[0537] An identity of 80% according to the above algorithm means 80% identity in the context of the present invention. The same applies to greater identities.
[0538] The feature "sequence which hybridizes, or, taking into consideration the degeneracy of the genetic code, would hybridize, with the counter strain of a sequence as specified in one of groups a) to d), especially preferably as specified in group a)," according to alternative e) indicates a sequence which hybridizes, or would hybridize taking into consideration the degeneracy of the genetic code, with the counter strand of a sequence as specified in one of groups a) to d), especially preferably as specified in group a), under preferably stringent conditions. For example, the hybridization reactions can be carried out at 68° C. in 2×SSC, or as described in the protocol of the dioxygenin labeling kit from Boehringer (Mannheim). Examples of preferred hybridization conditions are incubation overnight at 65° C. in 7% SDS, 1% BSA, 1 mM EDTA, 250 mM sodium phosphate buffer (pH 7.2), followed by washing at 65° C. with 2×SSC; 0.1% SDS.
[0539] The derivatives, of the isolated DNA according to the invention, which can be obtained according to alternative f) by substitution, addition, inversion and/or deletion of one or more bases of a sequence as specified in any of groups a) to e) include in particular those sequences which, in the protein which they encode, lead to conservative amino acid substitutions such as, for example, the substitution of glycine for alanine or of aspartate for glutamic acid. Such function-neutral mutations are referred to as sense mutations and do not lead to any principle modification of the activity of the polypeptide. It is furthermore known that modifications at the N and/or C terminus of a polypeptide do not have a considerable adverse effect on its function; indeed, they are even capable of stabilizing it, so that, as a consequence, the present invention also comprises DNA sequences where bases are added at the 3' terminus or at the 5' terminus of the sequence with the SEQ ID No 03. The skilled worker will find information on this subject in Ben Bassat et al. (Journal of Bacteriology 169:751-757 (1987)), in O'Regan et al. (Gene 77:237-251 (1989)), in Sahin-Toth et al. (Protein Sciences 3:240-247 (1994)), in Hochuli et al. (Bio/Technology 6: 1321-1325 (1988)) inter alia, and in known textbooks of Genetics and Molecular Biology.
[0540] To isolate the DNA according to the invention, an NADPH-dependant malonyl-coenzyme A reductase was first isolated from a cell extract of Metallosphaera sedula and purified. The first 20 amino acids of the N terminus of the polypeptide of the resulting purified enzyme were sequenced. The gene for the malonyl-coenzyme A reductase was subsequently determined in the genome of Sulfolobus tokodaii, which has already been fully sequenced (Kawarabayasi et al., "Complete genome sequence of an aerobic thermoacidophilic crenarchaeon, Sulfolobus tokodaii strain7.", DNA Research 8:123-40), by identifying the derived protein sequence which is identical with the first 20 amino acids of the polypeptide isolated from Metallosphaera sedula. The DNA sequence according to the invention was then amplified by means of PCR, using suitable primers (see example 2).
[0541] A contribution to solving the problems mentioned at the outset is furthermore contributed by a vector, preferably an expression vector, comprising a DNA with a sequence as specified in one of groups a) to f) as defined above. Suitable vectors are all vectors which are known to the skilled worker and which are traditionally employed for introducing DNA into a host cell. Preferred vectors are selected from the group consisting of plasmids, such as, for example, the E. coli plasmids pTrc99A, pBR345 and pBR322, viruses such as, for example, bacteriophages, adenoviruses, vaccinia viruses, baculoviruses, measles viruses and retroviruses, cosmids or YACs, with plasmids being most preferred as vectors.
[0542] According to a preferred embodiment of the vector according to the invention, the DNA with a sequence as specified in any of groups a) to f) is under the control of a promoter capable of being regulated, which promoter is suitable for expressing the polypeptide encoded by these DNA sequences in the cell of a microorganism, preferably in a bacterial cell, a yeast cell or a fungal cell, especially preferably in a bacterial cell, most preferably in an E. Coli cell. Examples of such promoters are the trp promoter or the tac promoter.
[0543] Besides a promoter, the vector according to the invention should preferably comprise a ribosomal binding site and terminator. Here, it is especially preferred that the DNA according to the invention is incorporated into an expression cassette of the vector comprising the promoter, the ribosomal binding site and terminator. Besides the abovementioned structural elements, the vector may furthermore comprise selection genes known to the skilled worker.
[0544] A contribution to solving the problems mentioned at the outset is furthermore provided by the use of the above-described vector for transforming a cell and by the cell obtained by transformation of this vector. The cells which can be transformed with the vector according to the invention may be prokaryotes or eukaryotes. They may take the form of mammalian cells (such as, for example, cells from humans), of plant cells or of microorganisms such as yeasts, fungi or bacteria, with microorganisms being especially preferred and bacteria and yeasts being most preferred.
[0545] A contribution to solving the problems mentioned at the outset is also provided by a polypeptide which features the amino acid sequence with the SEQ ID No 04 or an amino acid sequence which is obtained when no more than 40 amino acids, preferably no more than 20 amino acids, even more preferably no more than 10 amino acids and most preferably no more than 5 amino acids in SEQ ID No 04 are deleted, inserted, substituted or else added to the C and/or N terminus of the amino acid sequence with the SEQ ID No 04. The polypeptide takes the form of an enzyme which is capable of catalyzing both the conversion of (S)- or (R)-methylmalonyl-coenzyme A into (S)- or (R)-methylmalonate semialdehyde and the conversion of malonyl-coenzyme A into malonate semialdehyde. Such a polypeptide can be obtained for example via the synthetic route, starting from the DNA sequence with the SEQ ID No 03, or by transformation of a suitable cell with a suitable vector comprising this nucleic acid sequence, expression, in the cell, of the protein encoded by this nucleic acid sequence, lysis of the cell, generating a cell extract, and subsequent purification of the enzyme by means of purification techniques known to the skilled worker, for example by means of HPLC or other chromatographic methods. Besides chromatographic purification of the polypeptide from cell extracts, one can also exploit the advantage that the polypeptide with the amino acid sequence SEQ ID No 04 is heat-resistant up to a temperature of at least 75° C. The cell extract can therefore be heated to a temperature of, for example, 75° C., which results in the coagulation, and thus precipitation, in the cell extract of those polypeptides which are not heat resistant. The polypeptide with the amino acid sequence SEQ ID No 04 is retained in the cell extract in nondenatured form.
EXAMPLES
Example 1
[0546] The present invention is now illustrated in Example 1 with reference to a recombinant cell which is capable of producing 3-hydroxyisobutyric acid via 3-hydroxyiso-butyryl-coenzyme A as precursor and isobutyryl-coenzyme A as intermediate, starting from L-valine as carbon source. To this end, the enzymes EC 2.6.1.42 and EC 1.2.4.4 (in each case from Pseudomonas aeruginosa) and a cluster comprising the three enzymes EC 1.3.99.12, EC 4.2.1.17 and EC 3.1.2.4 (from Acinetobacter calcoaceticus) were overexpressed in E. coli BL21 (DE3).
[0547] Here, the enzyme EC 1.2.4.4 is encoded by a gene with the DNA sequence as shown in SEQ ID No 07 and 08 (α and β subunit), while the enzyme EC 2.6.1.42 is encoded by a gene with the DNA sequence as shown in SEQ ID No 09. The enzyme EC 1.3.99.12 is encoded by a gene with the DNA sequence with the SEQ ID No 10, the enzyme EC 4.2.1.17 by a gene with the DNA sequence as shown in SEQ ID No 11, and the enzyme EC 3.1.2.4 by a gene with the DNA sequence as shown in SEQ ID No 12.
[0548] 1. Organisms, Plasmids and Oligonucleotides
[0549] The following bacterial strains, vectors, genomic DNA and oligonucleotides were used for preparing this recombinant cell:
TABLE-US-00002
[0549] TABLE 1 Bacterial strains used Reference Strain (manufacturer) E. coli DH5 NEB E. coli BL21 (DE3) Invitrogen
TABLE-US-00003 TABLE 2 Vectors used Reference Vector (manufacturer) pCDFDuet-1 Novagen pET101/D-TOPO Invitrogen pCR2.1-TOPO Invitrogen
TABLE-US-00004 TABLE 3 Genomic DNA used Strain Pseudomonas aeruginosa PAO1 Acinetobacter calcoaceticus ADP1
TABLE-US-00005 TABLE 4 Oligonucleotides used Name Sequence Aca_VClus_fw 5'-ATGCAATTTAATGAAGAACAGCTATTAATTC- 3' (SEQ ID No. 13) Aca_VClus_rev 5'-CAGTCTGAAATGACTAACCTAATTGGC-3' (SEQ ID No. 14) Pae_26142_fw 5'-ACGGAATTCTGAAGGAGCTGGCAACTATG-3' (SEQ ID No 15) Pae_26142_rev 5'-TTGTCGACTTACTTGACCAGGGTACGCC-3' (SEQ ID No. 16) Pae_1244_fw 5'-ACAGATCTGGAGGCCTGTCATGAGTGATTAC- 3' (SEQ ID No. 17) Pae_1244_rev 5'-ATGGGTACCCATTCAGACCTCCATC-3' (SEQ ID No. 18)
[0550] 2. Amplification of the PCR Fragments 1.2.4.4 (2313 kb) and 2.6.1.42 (958 bp)
[0551] First, the fragments of 1.2.4.4 and 2.6.1.42 were amplified by means of PCR starting from the total DNA from Pseudomonas aeruginosa, using the primers as shown in SEQ ID No 15 to SEQ ID No 18, which are detailed in Table 4.
[0552] 3. Digestion of the Vector pCDF-Duet-1 and of the PCR Fragment 2.6.1.42 (958 bp)
[0553] The vector pCDFDuet-1 (featuring a streptomycin-/spectinomycin resistance) is cleaved by means of EcoRI/SalI, as is the PCR fragment 2.6.1.42, and the restrictions thus obtained are ligated overnight with T4 ligase. This gives rise to the vector pCDFDuet::2.6.1.42.
[0554] 4. Cloning of the PCR Fragments into the Vector pCR2.1-TOPO
[0555] The preparation of a cloning vector comprising the fragment 2.6.1.42 or the fragment 1.2.4.4, using the vector pCR2.1-TOPO, was performed as specified in the manufacturer's instructions. E. coli DH5α cells were transformed with the resulting cloning vectors pCR2.1-TOPO::1.2.4.4 and pCR2.1-TOPO::2.6.1.42. Since the pCR2.1-TOPO vectors feature a kanamycin resistance and an ampicillin resistance, the transformants were plated onto 2 AXI and KXI plates (20 and 40 μl). The plasmids of the resulting clones were isolated and digested:
[0556] pCR2.1-TOPO::1.2.4.4 BgIII+KpnI fragment size 2313 bp
[0557] pCR2.1-TOPO::2.6.1.42 EcoRI+SalI fragment size 958 bp
[0558] Each of the fragments was eluted from the gel and purified with the QIAquick kit from Qiagen (following instructions).
[0559] 5. Preparation of the Vector pCDFDuet:2.6.1.42-1.2.4.4
[0560] The vector pCDFDuet::2.6.1.42 and the vector pCR2.1-TOPO::1.2.4.4 are digested with BgIII/KpnI.
[0561] This is followed by the ligation of pCDFDuet::2.6.1.42 (BgIII/KpnI) with pCR2.1-TOPO::1.2.4.4, giving rise to the vector pCDFDuet::2.6.1.42-1.2.4.4. Again, E. coli DH5α cells were transformed by means of this cloning vector. The plasmids were isolated. The plasmid pCDFDuet::2.6.1.42-1.2.4.4 features the DNA sequence as shown in SEQ ID No 19.
[0562] 6. Cloning the Valine Cluster from Acinetobacter calcoaceticus (V-ClusAca)
[0563] Strain ATCC 33304 Acinetobacter calcoaceticus was cultured for the isolation of total DNA (HH agar or medium). Total DNA was isolated by means of the DNEasy kit from Qiagen (L1 and L2) and by a method comprising the method steps i) centrifugation of 1 ml of culture, ii) addition of 200 μl of H2O to the pellet, iii) heating for 10 min at 95° C., iv) centrifugation (10 min, 13 000 rpm), and v) removing the supernatant for a PCR.
[0564] To amplify the valine cluster from A. calcoaceticus, a PCR was carried out using the primers as shown in SEQ ID No 13 and SEQ ID No 14, which have been detailed in Table 4 (following the manufacturer's instructions using the polymerases Pfu and Taq, respectively).
[0565] The PCR products were purified and, following the instructions, ligated to the plasmid pET101/D-TOPO and transferred into E. coli DH5α. This gives rise to the plasmid pET101/D-TOPO::V-ClusterACA. Plasmid pET101/D-TOPO::V-ClusterAca features the DNA sequence as shown in SEQ ID No 20.
[0566] 7. Preparation of a Recombinant Cell which is Capable of Forming 3-Hydroxyisobutyric Acid from L-Valine
[0567] E. coli BL21 (DE3) was transformed with the plasmids pET101/D-TOPO::V-ClusterAcaand pCDF-Duet::2.6.1.42-1.2.4.4 (plated onto LB spec./amp medium). The resulting cells were capable of converting, in a nutrient medium comprising L-valine, the L-valine into 3-hydroxyisobutyric acid. In contrast, the wild type of the cells (E. coli BL21 (DE3)) was not capable of forming detectable amounts of 3-hydroxyisobutyric acid in such a nutrient medium.
Example 2
[0568] In this example, the DNA according to the invention is isolated and the gene is overexpressed in E. coli.
[0569] 1. Culturing and Harvesting Sulfolobus tokodaii
[0570] Sulfolobus tokodaii was grown in a small culture volume (40-200 ml) at 75° C. and a pH of 3.0, with shaking (150 rpm). The growth was monitored photometrically via measuring the optical density at 578 nm (OD578 nm). A modified Sulfolobus medium was used (modified as described by Brock et al., Archives of Microbiology 84, pages 54-68, 1972; Suzuki et al., Extremophiles, 6, pages 39-44, 2002). The energy and carbohydrate source used were yeast extract, casamino acids and glucose. The medium consisted of the following components: basal medium, glucose stock solution, iron stock solution and trace element stock solution. At an OD578nm of 0.3-0.5 (exponential phase), the cells were harvested. The centrifugation was carried out in a Sorvall centrifuge (SS34 rotor) for 15 min at 9000 rpm. The cell pellet was employed directly for the DNA extraction.
[0571] Basal medium. KH2PO4 (0.28 g/l, (NH4)2SO4 (1.3 g/l), MgSO4×7 H2O (0.25 g/l), CaCl2×6 H2O (0.07 g/l), yeast extract (1 g/l) and casamino acids (1 g/l). Before autoclaving, the pH was brought to 3.0 using H2SO4.
[0572] Glucose stock solution (100×). Glucose (100 g/l).
[0573] The solution was filter-sterilized.
[0574] Iron stock solution (1000×). FeCl3×6 H2O (20 g/l). The solution was filter-sterilized.
[0575] Trace element stock solution (1000×). MnCl2×4 H2O (1.8 g/l), Na2B4O7×10 H2O (4.5 g/l), ZnSO4×7 H2O (220 mg/l), CuCl2×2 H2O (50 mg/l), Na2MoO4×2 H2O (30 mg/l), VOSO4×5 H2O (30 mg/l), CoCl2×6 H2O (8.4 mg/l). The individual components were dissolved in succession in distilled H2O, the pH was brought to 3.0 using HCl, and the solution was filter-sterilized.
[0576] 2. Isolation of Genomic DNA from S. tokodaii
[0577] Genomic DNA was isolated by the method of Murray and Thompson (Nucleic Acid Research, 8, pages 4321-4325, 1980). To this end, 10-50 mg (fresh weight) of freshly harvested cells are weighed into a 1.5 ml Eppendorf reaction vessel and resuspended in 570 ml of TE buffer (10 mM Tris/HCl (pH 8.0), 1 mM NaEDTA). 30 μl of a 10% (w/v) SDS solution (sodium dodecyl sulfate solution) and 3 μl of Proteinase K (20 μg/μl) were added and the mixture was incubated for 1 h at 52° C. Thereafter, 100 μl of 5 M NaCl solution and 80 μl of pre-warmed 10% (w/v) cetyltrimethylammonium bromide (CTAB) solution (10% (w/v) CTAB in 0.7 M NaCl) were added. After incubation for 10 min at 65° C., the complexes of CTAB, cell wall fragments and proteins were extracted with 780 μl of chloroform/iso-amyl alcohol (24:1 (v/v)) and spun down for 15 min at 14 000 rpm. The aqueous top phase was transferred into a fresh Eppendorf reaction vessel and the extraction was repeated. After the aqueous phase was free from pigments, it was covered with a layer of 400 μl of 100% isopropanol. By carefully mixing the two phases, the chromosomal DNA precipitated at the interface. Then, it was possible to fish out the DNA with a drawn-out Pasteur pipette and washed in 200 μl of 70% ethanol. After recentrifugation (5 min, 14 000 rpm), the supernatant was pipetted off and the DNA was dried for 2 h at room temperature and finally dissolved in 100 μl of TE buffer.
[0578] 3. Amplification of the Malonyl-Coenzyme A Reductase Gene
[0579] The polymer chain reaction (PCR) (Mullis et al., Cold Spring Harbor Symp. Quant. Biol., 51, pages 263-273, 1986) was employed to amplify the malonyl-CoA reductase gene in a targeted fashion, from the genomic Sulfolobus tokodaii DNA obtained in Example 2. It was carried out in a thermocycler (Biometra, Gottingen).
[0580] A preparative PCR in which Pfu polymerase (Pfunds, Genaxxon) was used, was employed. The Pfu polymerase contains a 3'-5' exonuclease ("proofreading") function.
[0581] The following primers were used:
TABLE-US-00006
[0581] 5'-ATTATCCCATGGGGAGAACATTAAAAGC-3' ("forward primer"; NcoI cleavage site is underlined; SEQ ID No 21) and 5'-CGGGATCCTTACTTTTCAATATATCC-3' ("reverse primer"; BamHI cleavage site is underlined; SEQ ID No 22)
[0582] The reaction mixture detailed in Table 1 hereinbelow was employed for the PCR reactions. The PCR was carried out as a hot start PCR, i.e. the reaction mixture was incubated for 2 min at 95° C. before adding the Pfu polymerase. This was followed by 30 cycles of in each case 1 minute at 95° C., 1 minute at 45° C. and 5 minutes at 72° C., followed by a last step of 30 seconds at 45° C., 15 minutes at 72° C. and, finally, a pause at 6° C.
TABLE-US-00007
[0582] TABLE 1 Standard reaction mixtures (50 μl) for proofreading PCR with Pfu polymerase Composition μl/50 μl batch 10 × Pfu PCR 5 reaction buffer dNTP mix (2 mM per 5 nucleotide) Forward primer (2 μM) 12.5 Reverse primer (2 μM) 12.5 Chromosomal DNA 1 (10-50 ng) Pfu polymerase 2 (2.5 U/μl) dd-H2O 12
[0583] A gene fragment with a length of 1.1 kb was obtained.
[0584] 4. Cloning the Malonyl-Coenzyme a Reductase Gene
[0585] To clone the malonyl-coenzyme A reductase gene from Sulfolobus tokodaii, the gene amplified in Example 3 was cloned unspecifically with the vector pCR T7/CT-Topo (Invitrogen, Karlsruhe), using the "pCR T7 Topo TA Expression Kit" (Invitrogen, Karlsruhe). This was done following the manufacturer's instructions.
[0586] To isolate the plasmid DNA, the plasmid DNA was prepared using the "QIAprep Spin Plasmid Miniprep Kit" from Qiagen (Hilden) following the manufacturer's instructions, starting from 5 ml overnight cultures of transformed E. coli TOP10F' cells.
[0587] 5. Generation of an Expression Vector
[0588] To generate an expression vector comprising the malonyl-coenzyme A reductase gene, the isolated cloning vector obtained in Example 4 is subjected to restriction digestion with the restriction enzymes NcoI and BamHI. To this end, 25-27 μl of plasmid DNA (expression vector pTrc99A and pCR T7/CT-Topo vector, respectively, with the incorporated malonyl-coenzyme A reductase gene) are mixed thoroughly with 5 pa of a reaction buffer (10×) and 2-3 μl of restriction enzyme (10 U/μl; Fermentas, St. Leon-Rot). The reaction mixture was made up to 50 μl with distilled H2O and incubated for 5 h at the temperature specified by the manufacturer. An ethanol precipitation was carried out before further use. To this end, the DNA was mixed with 3 volumes of 100% ethanol and 0.1 volumes of 3 M sodium acetate buffer (pH 5.3) and incubated for 2 h or overnight at -80° C. After a centrifugation step (20 min, 14 000 rpm, 4° C., Eppendorf table-top centrifuge), the supernatant is removed carefully, and the DNA was washed with 3 volumes of 70% (v/v) ethanol. After 10 min incubation at room temperature, the mixture was recentrifuged (10 min, 14 000 rpm, 4° C., Eppendorf table-top centrifuge) and the supernatant was discarded. The DNA was then dried for 1 hour at room temperature and subsequently taken up in the desired volume of H2O or TE buffer (10 mM Tris/HCl (pH 8.0), 1 mM NaEDTA).
[0589] Then, alkaline phosphatase is used for removing the 5'-phosphate groups of the linearized double-stranded vector. In this manner, the cloning efficiency is increased since religation of the vector is prevented. Calf intestinal alkaline phosphatase was used for dephosphorylating the digested vector.
[0590] The dephosphorylation was carried out in the same buffer as the restriction digestion. 50 μl of restriction mixture were mixed with 1.5 μl of CIAP (Calf Intestine Alkaline Phosphatase (1U/μl; Fermentas, St. Leon-Rot) and the mixture was incubated for 30 min at 37° C. Before further use of the cleaved and dephosphorylated vector, an ethanol precipitation was carried out as described above.
[0591] T4 DNA ligase was used the ligation of the insert DNA with the expression vector, plasmid DNA and insert DNA being employed in a molar ratio of from 1:3-1:6.
[0592] Stock solutions:
[0593] Ligation buffer (10×): 0.5 M Tris/HCl, pH 7.6 100 mM MgCl2 0.5 mg/ml BSA filter-sterilized, storage at room temperature
[0594] 5 mM ATP (adenosine triphosphate) Always make up freshly in sterile distilled H2O
[0595] 50 mM DTE (dithioerythritol) Always make up freshly in ligation buffer
[0596] The ligation mixtures had a volume of 50 μl. Plasmid DNA (2-10 μl), insert DNA (2-20 μl), 5 μl of ligation buffer with DTE (50 mM) and the corresponding amount of sterile distilled H2O were pipetted together, vortexed, spun down briefly and subsequently incubated for 5 min at 45° C. The mixture was cooled on ice. 5 μl of 5 mM ATP and 1.5 μl of T4 DNA ligase (1 U/μl; Fermentas; St. Leon-Rot) were added, and everything was mixed. Ligation was performed overnight at 16° C.
[0597] The ligation mixture was employed directly for transforming chemically competent cells.
[0598] 6. Transformation of E. Coli Cells with the Expression Vector
[0599] A 5 ml overnight culture was grown starting from a single colony of E. coli Rosetta 2 cells. On the next morning, 50 ml of LB medium (Sambrook et al., "Molecular Cloning: A Laboratory Manual", Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989) were inoculated with 0.5-1.0 ml of this culture. After incubation for 1.5-2 h (37° C., shaking (180 rpm)), an OD578 nm of 0.6 was reached. The cells were cooled on ice for 10 min and subsequently spun down for 5 min at 5000 rpm and 4° C. (GSA rotor, Sorvall centrifuge). The supernatant was discarded and the cell pellet was resuspended in 2.7 ml of cold 0.1 M CaCl2 solution. After addition of 2.3 ml of sterile 50% (v/v) glycerol, the cell suspension was divided into portions (in each case 300 μl) in 1.5-ml Eppendorf reaction vessels. The competent cells were immediately frozen in liquid nitrogen and subsequently stored at -80° C.
[0600] To transform the cells, an aliquot of the chemically competent cells (300 μl) was defrosted on ice and treated with 25 μl of a ligation mixture. Everything was mixed carefully and incubated for 30 min on ice. After a heat shock (42° C., 1 min) the mixture was reincubated on ice for 5 min. Thereafter, 800 μl of LB medium (Sambrook et al., 1989) were added, and the cells were shaken for 1 h at 37° C. (Thermomixer, Eppendorf 5436). The mixture was concentrated and finally streaked onto LB medium. To this end, the mixture was spun down for 1 min at 10 000 rpm, 750 μm of the supernatant were discarded, and the cell pellet was resuspended. 50 μl, 100 μl and 200 μl of this concentrated mixture were streaked onto LB plates (Sambrook et al., 1989) supplemented with 100 μg/ml ampicillin and incubated overnight in the incubator at 37° C. The plates were washed with 1 ml LB medium. This cell suspension was used for subsequently inoculating 150 ml LB medium (supplemented with 100 μg/ml ampicillin) in 500 ml Erlenmeyer flasks with baffles. The cultures grew at 37° C. and 180 rpm. Overexpression was performed by inducing the promoter in pTrc99A by adding 0.5 M IPTG (isopropyl-(β-D-thiogalactopyranoside) at an OD578nm of 0.6. The induced cultures were incubated for 3 h under the abovementioned conditions and subsequently harvested at an OD578nm=2.7.
[0601] 7. Detection of the Enzymatic Activity
[0602] The E. coli strain obtained in Example 6 was disrupted by means of a cell mill. The disrupted cells were heated for 15 min at 85° C. During this heat precipitation, nonheat resistant enzymes coagulate and are precipitated. Since the target protein is heat resistant, it is retained in the supernatant. To measure the malonyl-coenzyme A reductase activity, the supernatant was diluted 1:50 in TM buffer (50 mM Tris/Cl, 1 mM MgCl2, pH 8.1). 30 μl of the diluted or undiluted (for detecting the methylmalonyl-coenzyme A reductase activity) supernatant were pipetted to 500 μl of HIPS buffer (100 mM HEPES/NaOH, 5 mM MgCl2, 1 mM dithioerythritol, containing 0.5 mM NADPH).
[0603] In a first batch, the reaction was started by adding malonyl-coenzyme A, the final concentration being 0.5 mM. The drop in the NADPH absorption at 365 nm was determined. The enzyme activity determined was 15.5 μmol/min/mg protein (15.5 U/mg).
[0604] In a second batch, the reaction was started by adding methylmalonyl-coenzyme A (from Fluka, Article No.: 67767), the final concentration being 2.0 mM. The drop in the NADPH absorption at 365 nm was determined. The enzyme activity determined was 0.24 μmol/min/mg protein (0.24 U/mg).
[0605] It can be seen from these results that the polypeptide which codes for the DNA sequence with the SEQ ID No 03 catalyzes both the conversion of malonyl-CoA and of methylmalonyl-coenzyme A.
[0606] 1 mol of NADPH was oxidized per mole of malonyl-CoA or methylmalonyl-Coa employed. From this it can be concluded that the enzymatic reaction leads to the corresponding semialdehyde.
Sequence CWU
1
1
2212214DNACorynebacterium glutamicum ATCC 13032 1atgacgtcga tccctaattt
ttcagacatc ccattgactg ctgagacacg tgcatcggag 60tcacacaacg ttgacgccgg
caaggtgtgg aacactcccg aaggcattga tgtcaagcgc 120gtattcacgc aggctgaccg
cgacgaggcg caagcggcgg gacatccggt ggattctttg 180ccaggtcaaa agccatttat
gcgcgggccg tacccaacta tgtacaccaa tcagccgtgg 240acgattcgcc agtacgcagg
cttttcaacc gccgcggaat ccaatgcgtt ttatcggagg 300aaccttgctg cgggtcaaaa
aggtttgtcg gttgcgttcg atctagcgac ccaccgcggt 360tatgactcgg ataatgagcg
cgtggtcggc gatgtgggta tggccggcgt ggcgattgat 420tcgattttgg atatgcgtca
gctgtttgat ggcattgatt tgtccagcgt gtcggtgtcg 480atgaccatga atggcgctgt
gctgccgatt cttgcgttct atatcgtggc ggctgaggaa 540caaggtgtgg gtccggagca
gcttgcgggc acgatccaga atgacatctt gaaagaattt 600atggtgcgca acacctatat
ttatccgccg aagccgtcga tgcgcatcat ttccaacatc 660tttgagtaca cctccttgaa
gatgccacgt tttaactcca tttcgatttc tggctatcac 720atccaggaag cgggagcgac
tgccgatttg gagctggcct acactctggc ggatggtatt 780gaatacatcc gtgcaggtaa
agaggtaggc cttgacgtgg ataagttcgc gcctcgtctg 840tccttcttct ggggtatttc
tatgtacacc ttcatggaga tcgcaaagct gcgtgcggga 900cgactgctgt ggagcgagtt
ggtggcaaaa ttcgatccga aaaacgccaa gtcccagtcg 960ctgcgcacgc actcgcagac
ctctggttgg tcgttgaccg cgcaggatgt gtacaacaac 1020gtcgcccgca ccgcgattga
ggcgatggct gcaacccagg gccacaccca gtcgctgcac 1080accaatgcac ttgatgaggc
gttggcgctg cccaccgatt tctctgctcg tatcgcccga 1140aacacccagc tgttgctgca
gcaggaatct ggcacggtgc gtccagttga tccatgggcg 1200ggctcctatt acgtggagtg
gttgaccaat gagctggcta accgcgcgcg caagcacatc 1260gatgaggtgg aggaagccgg
cggaatggcg caggccaccg cgcagggaat tcctaagctg 1320cgcattgagg aatcagcggc
acgcacccag gctcgcattg attccggccg ccaggcgctg 1380atcggcgtga atcgctacgt
ggcggaagaa gatgaggaaa ttgaagtcct caaggttgac 1440aacaccaagg ttcgcgcaga
acagttggct aaactcgcgc aactgaaagc agagcgcaac 1500gatgcggaag tcaaggctgc
gctggatgcg ttgacagctg ctgcccgcaa cgagcataaa 1560gagccagggg atttggatca
gaacctgctc aaacttgccg tcgatgctgc gcgcgcaaaa 1620gctaccattg gagagatctc
cgatgctttg gaagttgtct ttggccgcca cgaagcagaa 1680atcaggacgc tgtctggcgt
gtacaaggat gaggttggaa aggaaggcac agtgagcaac 1740gtcgaacgcg cgatcgccct
ggctgacgcc tttgaggctg aggaaggccg ccgcccacgt 1800atctttattg ccaagatggg
ccaggatgga catgaccgtg gacagaaggt tgtcgcgtct 1860gcctatgctg acctgggcat
ggacgtggat gttggaccgc tgtttcaaac tccagccgaa 1920gctgcccgcg ccgccgtgga
cgccgatgtt cacgtggtgg gtatgtcttc gctggcagca 1980ggccacctca ccttgctgcc
cgagctgaag aaagaacttg cagctcttgg ccgcgatgac 2040attctggtca ccgtgggcgg
cgtcattccg ccgggcgatt tccaggatct ctacgatatg 2100ggtgccgccg cgatttaccc
tccaggaacc gtcatcgcgg agtcggcgat cgatctgatc 2160acccgactcg ccgcacacct
gggctttgac ctggatgtgg atgtgaatga gtga 22142737PRTCorynebacterium
glutamicum ATCC 13032 2Met Thr Ser Ile Pro Asn Phe Ser Asp Ile Pro Leu
Thr Ala Glu Thr 1 5 10
15 Arg Ala Ser Glu Ser His Asn Val Asp Ala Gly Lys Val Trp Asn Thr
20 25 30 Pro Glu Gly
Ile Asp Val Lys Arg Val Phe Thr Gln Ala Asp Arg Asp 35
40 45 Glu Ala Gln Ala Ala Gly His Pro
Val Asp Ser Leu Pro Gly Gln Lys 50 55
60 Pro Phe Met Arg Gly Pro Tyr Pro Thr Met Tyr Thr Asn
Gln Pro Trp 65 70 75
80 Thr Ile Arg Gln Tyr Ala Gly Phe Ser Thr Ala Ala Glu Ser Asn Ala
85 90 95 Phe Tyr Arg Arg
Asn Leu Ala Ala Gly Gln Lys Gly Leu Ser Val Ala 100
105 110 Phe Asp Leu Ala Thr His Arg Gly Tyr
Asp Ser Asp Asn Glu Arg Val 115 120
125 Val Gly Asp Val Gly Met Ala Gly Val Ala Ile Asp Ser Ile
Leu Asp 130 135 140
Met Arg Gln Leu Phe Asp Gly Ile Asp Leu Ser Ser Val Ser Val Ser 145
150 155 160 Met Thr Met Asn Gly
Ala Val Leu Pro Ile Leu Ala Phe Tyr Ile Val 165
170 175 Ala Ala Glu Glu Gln Gly Val Gly Pro Glu
Gln Leu Ala Gly Thr Ile 180 185
190 Gln Asn Asp Ile Leu Lys Glu Phe Met Val Arg Asn Thr Tyr Ile
Tyr 195 200 205 Pro
Pro Lys Pro Ser Met Arg Ile Ile Ser Asn Ile Phe Glu Tyr Thr 210
215 220 Ser Leu Lys Met Pro Arg
Phe Asn Ser Ile Ser Ile Ser Gly Tyr His 225 230
235 240 Ile Gln Glu Ala Gly Ala Thr Ala Asp Leu Glu
Leu Ala Tyr Thr Leu 245 250
255 Ala Asp Gly Ile Glu Tyr Ile Arg Ala Gly Lys Glu Val Gly Leu Asp
260 265 270 Val Asp
Lys Phe Ala Pro Arg Leu Ser Phe Phe Trp Gly Ile Ser Met 275
280 285 Tyr Thr Phe Met Glu Ile Ala
Lys Leu Arg Ala Gly Arg Leu Leu Trp 290 295
300 Ser Glu Leu Val Ala Lys Phe Asp Pro Lys Asn Ala
Lys Ser Gln Ser 305 310 315
320 Leu Arg Thr His Ser Gln Thr Ser Gly Trp Ser Leu Thr Ala Gln Asp
325 330 335 Val Tyr Asn
Asn Val Ala Arg Thr Ala Ile Glu Ala Met Ala Ala Thr 340
345 350 Gln Gly His Thr Gln Ser Leu His
Thr Asn Ala Leu Asp Glu Ala Leu 355 360
365 Ala Leu Pro Thr Asp Phe Ser Ala Arg Ile Ala Arg Asn
Thr Gln Leu 370 375 380
Leu Leu Gln Gln Glu Ser Gly Thr Val Arg Pro Val Asp Pro Trp Ala 385
390 395 400 Gly Ser Tyr Tyr
Val Glu Trp Leu Thr Asn Glu Leu Ala Asn Arg Ala 405
410 415 Arg Lys His Ile Asp Glu Val Glu Glu
Ala Gly Gly Met Ala Gln Ala 420 425
430 Thr Ala Gln Gly Ile Pro Lys Leu Arg Ile Glu Glu Ser Ala
Ala Arg 435 440 445
Thr Gln Ala Arg Ile Asp Ser Gly Arg Gln Ala Leu Ile Gly Val Asn 450
455 460 Arg Tyr Val Ala Glu
Glu Asp Glu Glu Ile Glu Val Leu Lys Val Asp 465 470
475 480 Asn Thr Lys Val Arg Ala Glu Gln Leu Ala
Lys Leu Ala Gln Leu Lys 485 490
495 Ala Glu Arg Asn Asp Ala Glu Val Lys Ala Ala Leu Asp Ala Leu
Thr 500 505 510 Ala
Ala Ala Arg Asn Glu His Lys Glu Pro Gly Asp Leu Asp Gln Asn 515
520 525 Leu Leu Lys Leu Ala Val
Asp Ala Ala Arg Ala Lys Ala Thr Ile Gly 530 535
540 Glu Ile Ser Asp Ala Leu Glu Val Val Phe Gly
Arg His Glu Ala Glu 545 550 555
560 Ile Arg Thr Leu Ser Gly Val Tyr Lys Asp Glu Val Gly Lys Glu Gly
565 570 575 Thr Val
Ser Asn Val Glu Arg Ala Ile Ala Leu Ala Asp Ala Phe Glu 580
585 590 Ala Glu Glu Gly Arg Arg Pro
Arg Ile Phe Ile Ala Lys Met Gly Gln 595 600
605 Asp Gly His Asp Arg Gly Gln Lys Val Val Ala Ser
Ala Tyr Ala Asp 610 615 620
Leu Gly Met Asp Val Asp Val Gly Pro Leu Phe Gln Thr Pro Ala Glu 625
630 635 640 Ala Ala Arg
Ala Ala Val Asp Ala Asp Val His Val Val Gly Met Ser 645
650 655 Ser Leu Ala Ala Gly His Leu Thr
Leu Leu Pro Glu Leu Lys Lys Glu 660 665
670 Leu Ala Ala Leu Gly Arg Asp Asp Ile Leu Val Thr Val
Gly Gly Val 675 680 685
Ile Pro Pro Gly Asp Phe Gln Asp Leu Tyr Asp Met Gly Ala Ala Ala 690
695 700 Ile Tyr Pro Pro
Gly Thr Val Ile Ala Glu Ser Ala Ile Asp Leu Ile 705 710
715 720 Thr Arg Leu Ala Ala His Leu Gly Phe
Asp Leu Asp Val Asp Val Asn 725 730
735 Glu 31071DNASulfolobus tokodaii 3atgaggagaa cattaaaagc
cgcaatatta ggtgctactg gtttagtagg aatcgaatac 60gtaagaatgc tatcaaatca
tccttatatt aaaccagcat atttagctgg aaaaggttca 120gtgggtaaac cgtatggtga
ggtagtaaga tggcaaacag taggacaagt tcctaaggaa 180atagctgata tggaaataaa
accaactgat cctaagttaa tggatgatgt agacataata 240ttttctccat tacctcaagg
tgctgctggc ccagtagaag aacaatttgc aaaagaagga 300ttccctgtga ttagtaattc
accagatcat agatttgatc ctgatgttcc cttattggtt 360cctgaactaa atcctcatac
tattagctta attgatgagc aaagaaaaag aagagaatgg 420aaaggattta tagtaactac
accactatgc acagcccagg gtgcagcaat accattaggt 480gctatattta aagattataa
gatggatgga gcatttataa ctactattca atcgctatct 540ggtgccggtt atccaggaat
accatcatta gatgtagtag ataatatctt gcctttaggt 600gatggatacg atgccaagac
gataaaagag atcttcagaa ttttaagcga agttaagaga 660aatgtagatg aacctaaatt
agaagatgta agcttagcag caacaactca tagaatagct 720actatacatg gtcattatga
agtactatat gtatcgttca aagaggaaac tgctgctgaa 780aaagttaagg agactttaga
aaactttaga ggggaaccac aagatctaaa attaccaact 840gcaccttcaa agccaattat
cgttatgaat gaggatacaa gacctcaagt ctattttgat 900agatgggctg gggatattcc
aggaatgagt gtagttgtag gtagattaaa gcaagtgaat 960aagagaatga taaggttagt
atcattaatt cataacacgg tcagaggagc cgcaggagga 1020ggtatattag cagctgaatt
acttgtcgaa aaaggatata ttgaaaagta a 10714356PRTSulfolobus
tokodaii 4Met Arg Arg Thr Leu Lys Ala Ala Ile Leu Gly Ala Thr Gly Leu Val
1 5 10 15 Gly Ile
Glu Tyr Val Arg Met Leu Ser Asn His Pro Tyr Ile Lys Pro 20
25 30 Ala Tyr Leu Ala Gly Lys Gly
Ser Val Gly Lys Pro Tyr Gly Glu Val 35 40
45 Val Arg Trp Gln Thr Val Gly Gln Val Pro Lys Glu
Ile Ala Asp Met 50 55 60
Glu Ile Lys Pro Thr Asp Pro Lys Leu Met Asp Asp Val Asp Ile Ile 65
70 75 80 Phe Ser Pro
Leu Pro Gln Gly Ala Ala Gly Pro Val Glu Glu Gln Phe 85
90 95 Ala Lys Glu Gly Phe Pro Val Ile
Ser Asn Ser Pro Asp His Arg Phe 100 105
110 Asp Pro Asp Val Pro Leu Leu Val Pro Glu Leu Asn Pro
His Thr Ile 115 120 125
Ser Leu Ile Asp Glu Gln Arg Lys Arg Arg Glu Trp Lys Gly Phe Ile 130
135 140 Val Thr Thr Pro
Leu Cys Thr Ala Gln Gly Ala Ala Ile Pro Leu Gly 145 150
155 160 Ala Ile Phe Lys Asp Tyr Lys Met Asp
Gly Ala Phe Ile Thr Thr Ile 165 170
175 Gln Ser Leu Ser Gly Ala Gly Tyr Pro Gly Ile Pro Ser Leu
Asp Val 180 185 190
Val Asp Asn Ile Leu Pro Leu Gly Asp Gly Tyr Asp Ala Lys Thr Ile
195 200 205 Lys Glu Ile Phe
Arg Ile Leu Ser Glu Val Lys Arg Asn Val Asp Glu 210
215 220 Pro Lys Leu Glu Asp Val Ser Leu
Ala Ala Thr Thr His Arg Ile Ala 225 230
235 240 Thr Ile His Gly His Tyr Glu Val Leu Tyr Val Ser
Phe Lys Glu Glu 245 250
255 Thr Ala Ala Glu Lys Val Lys Glu Thr Leu Glu Asn Phe Arg Gly Glu
260 265 270 Pro Gln Asp
Leu Lys Leu Pro Thr Ala Pro Ser Lys Pro Ile Ile Val 275
280 285 Met Asn Glu Asp Thr Arg Pro Gln
Val Tyr Phe Asp Arg Trp Ala Gly 290 295
300 Asp Ile Pro Gly Met Ser Val Val Val Gly Arg Leu Lys
Gln Val Asn 305 310 315
320 Lys Arg Met Ile Arg Leu Val Ser Leu Ile His Asn Thr Val Arg Gly
325 330 335 Ala Ala Gly Gly
Gly Ile Leu Ala Ala Glu Leu Leu Val Glu Lys Gly 340
345 350 Tyr Ile Glu Lys 355
51293DNARhodobacter sphaeroides 5atggccctcg acgtgcagag cgatatcgtc
gcctacgacg cgcccaagaa ggacctctac 60gagatcggcg agatgccgcc tctcggccat
gtgccgaagg agatgtatgc ttgggccatc 120cggcgcgagc gtcatggcga gccggatcag
gccatgcaga tcgaggtggt cgagacgccc 180tcgatcgaca gccacgaggt gctcgttctc
gtgatggcgg cgggcgtgaa ctacaacggc 240atctgggccg gcctcggcgt gcccgtctcg
ccgttcgacg gtcacaagca gccctatcac 300atcgcgggct ccgacgcgtc gggcatcgtc
tgggcggtgg gcgacaaggt caagcgctgg 360aaggtgggcg acgaggtcgt gatccactgc
aaccaggacg acggcgacga cgaggaatgc 420aacggcggcg acccgatgtt ctcgcccacc
cagcggatct ggggctacga gacgccggac 480ggctccttcg cccagttcac ccgcgtgcag
gcgcagcagc tgatgaagcg tccgaagcac 540ctgacctggg aagaggcggc ctgctacacg
ctgaccctcg ccaccgccta ccggatgctc 600ttcggccaca agccgcacga cctgaagccg
gggcagaacg tgctggtctg gggcgcctcg 660ggcggcctcg gctcctacgc gatccagctc
atcaacacgg cgggcgccaa tgccatcggc 720gtcatctcag aggaagacaa gcgcgacttc
gtcatggggc tgggcgccaa gggcgtcatc 780aaccgcaagg acttcaagtg ctggggccag
ctgcccaagg tgaactcgcc cgaatataac 840gagtggctga aggaggcgcg caagttcggc
aaggccatct gggacatcac cggcaagggc 900atcaacgtcg acatggtgtt cgaacatccg
ggcgaggcga ccttcccggt ctcgtcgctg 960gtggtgaaga agggcggcat ggtcgtgatc
tgcgcgggca ccaccggctt caactgcacc 1020ttcgacgtcc gctacatgtg gatgcaccag
aagcgcctgc agggcagcca tttcgccaac 1080ctcaagcagg cctccgcggc caaccagctg
atgatcgagc gccgcctcga tccctgcatg 1140tccgaggtct tcccctgggc cgagatcccg
gctgcccata cgaagatgta taagaaccag 1200cacaagcccg gcaacatggc ggtgctggtg
caggccccgc gcacggggtt gcgcaccttc 1260gccgacgtgc tcgaggccgg ccgcaaggcc
tga 12936430PRTRhodobacter sphaeroides
6Met Ala Leu Asp Val Gln Ser Asp Ile Val Ala Tyr Asp Ala Pro Lys 1
5 10 15 Lys Asp Leu Tyr
Glu Ile Gly Glu Met Pro Pro Leu Gly His Val Pro 20
25 30 Lys Glu Met Tyr Ala Trp Ala Ile Arg
Arg Glu Arg His Gly Glu Pro 35 40
45 Asp Gln Ala Met Gln Ile Glu Val Val Glu Thr Pro Ser Ile
Asp Ser 50 55 60
His Glu Val Leu Val Leu Val Met Ala Ala Gly Val Asn Tyr Asn Gly 65
70 75 80 Ile Trp Ala Gly Leu
Gly Val Pro Val Ser Pro Phe Asp Gly His Lys 85
90 95 Gln Pro Tyr His Ile Ala Gly Ser Asp Ala
Ser Gly Ile Val Trp Ala 100 105
110 Val Gly Asp Lys Val Lys Arg Trp Lys Val Gly Asp Glu Val Val
Ile 115 120 125 His
Cys Asn Gln Asp Asp Gly Asp Asp Glu Glu Cys Asn Gly Gly Asp 130
135 140 Pro Met Phe Ser Pro Thr
Gln Arg Ile Trp Gly Tyr Glu Thr Pro Asp 145 150
155 160 Gly Ser Phe Ala Gln Phe Thr Arg Val Gln Ala
Gln Gln Leu Met Lys 165 170
175 Arg Pro Lys His Leu Thr Trp Glu Glu Ala Ala Cys Tyr Thr Leu Thr
180 185 190 Leu Ala
Thr Ala Tyr Arg Met Leu Phe Gly His Lys Pro His Asp Leu 195
200 205 Lys Pro Gly Gln Asn Val Leu
Val Trp Gly Ala Ser Gly Gly Leu Gly 210 215
220 Ser Tyr Ala Ile Gln Leu Ile Asn Thr Ala Gly Ala
Asn Ala Ile Gly 225 230 235
240 Val Ile Ser Glu Glu Asp Lys Arg Asp Phe Val Met Gly Leu Gly Ala
245 250 255 Lys Gly Val
Ile Asn Arg Lys Asp Phe Lys Cys Trp Gly Gln Leu Pro 260
265 270 Lys Val Asn Ser Pro Glu Tyr Asn
Glu Trp Leu Lys Glu Ala Arg Lys 275 280
285 Phe Gly Lys Ala Ile Trp Asp Ile Thr Gly Lys Gly Ile
Asn Val Asp 290 295 300
Met Val Phe Glu His Pro Gly Glu Ala Thr Phe Pro Val Ser Ser Leu 305
310 315 320 Val Val Lys Lys
Gly Gly Met Val Val Ile Cys Ala Gly Thr Thr Gly 325
330 335 Phe Asn Cys Thr Phe Asp Val Arg Tyr
Met Trp Met His Gln Lys Arg 340 345
350 Leu Gln Gly Ser His Phe Ala Asn Leu Lys Gln Ala Ser Ala
Ala Asn 355 360 365
Gln Leu Met Ile Glu Arg Arg Leu Asp Pro Cys Met Ser Glu Val Phe 370
375 380 Pro Trp Ala Glu Ile
Pro Ala Ala His Thr Lys Met Tyr Lys Asn Gln 385 390
395 400 His Lys Pro Gly Asn Met Ala Val Leu Val
Gln Ala Pro Arg Thr Gly 405 410
415 Leu Arg Thr Phe Ala Asp Val Leu Glu Ala Gly Arg Lys Ala
420 425 430 71233DNAPseudomonas
aeruginosa 7atgagtgatt acgagccgtt gcgtctgcat gtcccggagc ccaccgggcg
tcctggctgc 60aagaccgact tttcctatct gcacctgtcc cccgccggcg aggtacgcaa
gccgccggtg 120gatgtcgagc ccgccgagac cagcgacctg gcctacagcc tggtacgtgt
gctcgacgac 180gacggccacg ccgtcggtcc ctggaatccg cagctcagca acgaacaact
gctgcgcggc 240atgcgggcga tgctcaagac ccgcctgttc gacgcgcgca tgctcaccgc
gcaacggcag 300aaaaagcttt ccttctatat gcaatgcctc ggcgaggaag ccatcgccac
cgcccacacc 360ctggccctgc gcgacggcga catgtgcttt ccgacctatc gccagcaagg
catcctgatc 420acccgcgaat acccgctggt ggacatgatc tgccagcttc tctccaacga
ggccgacccg 480ctcaagggcc gccagctgcc gatcatgtac tcgagcaagg aggcaggttt
cttctccatc 540tccggcaacc tcgccaccca gttcatccag gcggtcggct ggggcatggc
ctcggcgatc 600aagggcgaca cgcgcatcgc ctcggcctgg atcggcgacg gcgccaccgc
cgagtcggac 660ttccacaccg ccctcacctt cgcccatgtc taccgcgcgc cggtaatcct
caacgtggtc 720aacaaccagt gggcgatctc caccttccag gccatcgccg gcggcgaagg
caccaccttc 780gccaaccgtg gcgtgggctg cgggatcgcc tcgctgcggg tcgacggcaa
tgacttcctg 840gcggtctacg ccgcctccga gtgggccgcc gagcgcgccc ggcgcaacct
cgggccgagc 900ctgatcgaat gggtcaccta ccgcgccggc ccgcactcga cttcggacga
cccgtccaag 960taccgccccg ccgacgactg gaccaacttc ccgctgggcg acccgatcgc
ccgcctgaag 1020cggcacatga tcggcctcgg catctggtcg gaggaacagc acgaagccac
ccacaaggcc 1080ctcgaagccg aagtactggc cgcgcagaaa caggcggaga gccatggcac
cctgatcgac 1140ggccgggtgc cgagcgccgc cagcatgttc gaggacgtct atgcagaact
gccggagcac 1200ctgcgccggc aacgccagga gctcggggta tga
123381049DNAPseudomonas aeruginosa 8atgccatgaa cccgcaacac
gagaacgccc agacggtcac cagcatgacc atgatccagg 60cgctgcgctc ggcgatggac
atcatgctcg agcgcgacga cgacgtggtg gtattcggcc 120aggacgtcgg ctacttcggc
ggcgtgttcc gctgcaccga aggcctgcag aagaaatacg 180gcacctcgcg ggtgttcgat
gcgccgatct ccgagagcgg catcatcggc gccgcggtcg 240gcatgggtgc ctacggcctg
cgcccggtgg tggagatcca gttcgccgac tacgtctacc 300cggcctccga ccagttgatc
tccgaggcgg cgcgcctgcg ctatcgctcg gccggcgact 360tcatcgtgcc gatgaccgta
cgcatgccct gtggcggcgg catctacggc gggcaaacgc 420acagccagag cccggaggcg
atgttcaccc aggtctgcgg cctgcgcacg gtgatgccgt 480ccaaccccta cgacgccaag
ggcctgctga tcgcctgcat cgagaacgac gacccggtga 540tcttcctcga gcccaagcgc
ctctacaacg gcccgttcga tggccaccac gaccgcccgg 600tgacgccctg gtccaagcat
ccggccagcc aggtgccgga cggctactac aaggtgccgc 660tggacaaggc ggcgatcgtc
cgccccggcg cggcgctgac cgtgctgacc tacggcacca 720tggtctacgt ggcccaggcc
gcggccgacg agaccggcct ggacgccgag atcatcgacc 780tgcgcagcct ctggccgctg
gacctggaaa ccatcgtcgc ctcggtgaag aagaccggcc 840gctgcgtcat cgcccacgag
gcgacccgca cctgcgggtt cggcgccgag ctgatgtcgc 900tggtgcagga gcactgcttc
caccacctgg aggcgccgat cgagcgcgtc accggttggg 960acacccccta cccgcatgcc
caggagtggg cgtatttccc cggccccgcg cgcgtcggcg 1020cggcattcaa gcgtgtgatg
gaggtctga 10499924DNAPseudomonas
aeruginosa 9atgtcgatgg ccgatcgtga tggcgtgatc tggtatgacg gtgaactggt
gcagtggcgc 60gacgcgacca cgcacgtgct gacccatacc ctgcactatg gaatgggcgt
gttcgagggc 120gtgcgcgcct acgacacccc gcagggcacg gcgatcttcc gcctgcaggc
gcataccgac 180cggctgttcg actccgcgca catcatgaac atgcagatcc cgtacagccg
cgacgagatc 240aacgaggcga cccgcgccgc cgtgcgcgag aacaacctgg aaagcgccta
tatccgcccg 300atggtgttct acggaagcga aggcatgggc ctgcgcgcca gcggcctgaa
ggtccatgtg 360atcatcgccg cctggagctg gggcgcctac atgggcgagg aagccctgca
gcaaggcatc 420aaggtgcgca ccagttcctt cacccgccac cacgtcaaca tctcgatgac
ccgcgccaag 480tccaacggcg cctacatcaa ctcgatgctg gccctccagg aagcgatctc
cggcggcgcc 540gacgaggcca tgatgctcga tccggaaggc tacgtggccg aaggctccgg
cgagaacatc 600ttcatcatca aggatggcgt gatctacacc ccggaagtca ccgcctgcct
gaacggcatc 660actcgtaaca ctatcctgac cctggccgcc gaacacggtt ttaaactggt
cgagaagcgc 720atcacccgcg acgaggtgta catcgccgac gaggccttct tcactggcac
tgccgcggaa 780gtcacgccga tccgcgaagt ggacggtcgc aagatcggcg ccggccgccg
tggcccggtc 840accgaaaagc tgcagaaagc ctatttcgac ctggtcagcg gcaagaccga
ggcccacgcc 900gagtggcgta ccctggtcaa gtaa
924101128DNAAcinetobacter calcoaceticus 10atgcaattta
atgaagaaca gctattaatt caggatatgg cgaaaagttt tgccaatgaa 60cagattaaat
ctaatgcagc agaatgggat aagcatagca tttttccaaa agacgttttg 120tcccaaatgg
ggcaattggg ttttatggga atgctggtga gtgagaaatg gggcggatca 180aatacaggaa
atttagctta tgtgctggca cttgaagaaa tcgctgccgc agatggtgcg 240acttcaacca
ttatgagtgt acataattct gttggctgtg tacccattgc taaatttggt 300acagaggagc
aaaagcagaa atatctagtg cctttagcac aaggtgaaat gatcggtgca 360tttgctttaa
cggaaccaca tacaggttcc gatgccgcag ccattaaaac ccgagcaatt 420aaacaaggtg
atgaatggat tattaatggc gctaaacaat ttataacatc aggtcataat 480gcgggcgtga
ttattgtatt tgctgtgaca gatccgaatg cagggaaaaa agggctgagt 540gcatttattg
tgccgcgtga aaccttgggt tatgaggtga ttcgcaccga agaaaaattg 600ggtttacatg
cgtcagatac gtgccaaatt gctttaacgg atgttcgagt acatcacagc 660ttaatgcttg
gtcaggaagg tgagggacta aaaatagcat tgtctaatct ggaaggtggc 720cgtattggga
ttgcagcgca agccgttggt ttggcacgtg ctgcactaga agaagcgaca 780aaatatgcca
aagagcgtgt gacctttgga aagcctattt ttgagcatca ggcgttagcc 840tttcgtttag
ccagtatggc cacagaaatt gaagcagcac gacaattggt tcattacgca 900gcgcggctta
aagaagctgg aaaaccttgt ttaaatgaag catcaatggc gaaattattt 960tcatctgaaa
tggtcgaacg cgtatgttct gctgctttgc aaatctttgg tggctatggc 1020tatttaaaag
actttcccat cgagcgaatt tatcgtgatg cacgtatttg ccagatttat 1080gaaggtacaa
gtgatattca gcgtttagtg atagcaagaa gcctataa
112811774DNAAcinetobacter calcoaceticus 11atgacattcg caacaatttt
attggaaaaa cgtaagggtg tgggcttgat tacacttaac 60cgtccaaaag cattaaatgc
tttaaactca gaattaattt atgaaataaa tttagcctta 120gacgatttag aaaatgatca
aacgattggt tgtatcgtcc ttacaggttc agaaaaagcc 180tttgccgcag gtgcggatat
caaagaaatg gcagaattaa cttttccaaa tatttatttt 240gatgattttt ttagtcttgc
agatcgtatt gcacagcgtc gtaagccttt aattgccgca 300gtgagtggtt atgctttagg
tggtggctgt gagttagcac tcatgtgtga ctttatttat 360tgtgccgaca atgccaagtt
tgcactacca gaagtaactt taggtgtcat tcctggtatt 420ggtggaacac agcgtctaac
gcttgcaata ggcaaagcca aagccatgga aatgtgtttg 480actgcacggc aaatgcaggc
tgctgaggca gaacaaagtg gtttggtggc acgcgttttt 540agtaaagaag aacttttaga
acaaacctta caggctgccg aaaaaatagc ggaaaaatca 600cgggtatcta ccataatgat
taaagagtca attaatcgag cttttgaagt gagtttagca 660gagggtttac gttttgagcg
ccgaatgttc cattcagttt ttgcgacctt agatcagaaa 720gaaggcatgc aagcatttat
tgataaacgt ccagcccaat ttaaacatca ataa 774121029DNAAcinetobacter
calcoaceticus 12atgactacta ctgacaatca tttactcatt gaacataaaa acgctttagg
aacaattatt 60ttaaatcgtc cagcgagtct gaacgcgcta tctctagaaa tgattaatgc
gattcgtcaa 120caagttgagg attggcaagg tgatgtaaat gttcaggcca tattaattaa
atcaaatagt 180cctaaagcat tttgtgcagg tggtgatatt cgctatcttt atgaaagtta
taaaagtgga 240tcagaagagt ataaagatta tttcattgct gaatatgaga tgctcaatag
cattcgaacg 300tctaaaaaaa cagtgattgt tttattggat ggatatgtat tgggtggtgg
ttttggttta 360gcacaggctt gtcatatctt ggtgagtagt gaaaaatcac gattttcaat
gccagaaaca 420gcaataggtt ttttcccaga tgttgcagcg acttatttct tatctcgttt
agatgatgtt 480ggggtatatt tggcactgac tggtgatcaa atcagtagta gtgatgcatt
gtatttagat 540ctgattgatt atcatgttcc gagtcagaat tttgagcgac tagaaaatgc
attcagccaa 600tcacagaact tagataaatt tcatattcag aagattattt ctgcttatat
ctccagccct 660gttcagagtg aactcagtct atggcttgaa gccattcgtc agcattttgg
tcttaaaaat 720gtgcaagata tcgaagaaag tttgaaaaat gaacaagatc ccaactatca
agtatggaca 780agtaaagtgt taaatacttt gcaacaacgt tcctctattg caaaaaaaac
cagtttaaag 840ttacagctgc tagggcgtgg atggtcatta cagcaatgta tgcgtatcga
gcgaaaatta 900caggatatct ggtttgaaca tggtgatatg attgagggtg ttcgagcgtt
gattattgat 960aaagataaac aaccgcaatg gcagcagcat aatgcgactt tagataatat
attaggccaa 1020ttaggttag
10291331DNAArtificial SequenceDescription of Artificial
Sequence Synthetic primer 13atgcaattta atgaagaaca gctattaatt c
311427DNAArtificial SequenceDescription of
Artificial Sequence Synthetic primer 14cagtctgaaa tgactaacct aattggc
271529DNAArtificial
SequenceDescription of Artificial Sequence Synthetic primer
15acggaattct gaaggagctg gcaactatg
291628DNAArtificial SequenceDescription of Artificial Sequence Synthetic
primer 16ttgtcgactt acttgaccag ggtacgcc
281731DNAArtificial SequenceDescription of Artificial Sequence
Synthetic primer 17acagatctgg aggcctgtca tgagtgatta c
311825DNAArtificial SequenceDescription of Artificial
Sequence Synthetic primer 18atgggtaccc attcagacct ccatc
25196960DNAArtificial SequenceDescription of
Artificial Sequence Synthetic plasmid polynucleotide 19ggggaattgt
gagcggataa caattcccct gtagaaataa ttttgtttaa ctttaataag 60gagatatacc
atgggcagca gccatcacca tcatcaccac agccaggatc cgaattctga 120aggagctggc
aactatgtcg atggccgatc gtgatggcgt gatctggtat gacggtgaac 180tggtgcagtg
gcgcgacgcg accacgcacg tgctgaccca taccctgcac tatggaatgg 240gcgtgttcga
gggcgtgcgc gcctacgaca ccccgcaggg cacggcgatc ttccgcctgc 300aggcgcatac
cgaccggctg ttcgactccg cgcacatcat gaacatgcag atcccgtaca 360gccgcgacga
gatcaacgag gcgacccgcg ccgccgtgcg cgagaacaac ctggaaagcg 420cctatatccg
cccgatggtg ttctacggaa gcgaaggcat gggcctgcgc gccagcggcc 480tgaaggtcca
tgtgatcatc gccgcctgga gctggggcgc ctacatgggc gaggaagccc 540tgcagcaagg
catcaaggtg cgcaccagtt ccttcacccg ccaccacgtc aacatctcga 600tgacccgcgc
caagtccaac ggcgcctaca tcaactcgat gctggccctc caggaagcga 660tctccggcgg
cgccgacgag gccatgatgc tcgatccgga aggctacgtg gccgaaggct 720ccggcgagaa
catcttcatc atcaaggatg gcgtgatcta caccccggaa gtcaccgcct 780gcctgaacgg
catcactcgt aacactatcc tgaccctggc cgccgaacac ggttttaaac 840tggtcgagaa
gcgcatcacc cgcgacgagg tgtacatcgc cgacgaggcc ttcttcactg 900gcactgccgc
ggaagtcacg ccgatccgcg aagtggacgg tcgcaagatc ggcgccggcc 960gccgtggccc
ggtcaccgaa aagctgcaga aagcctattt cgacctggtc agcggcaaga 1020ccgaggccca
cgccgagtgg cgtaccctgg tcaagtaagt cgacaagctt gcggccgcat 1080aatgcttaag
tcgaacagaa agtaatcgta ttgtacacgg ccgcataatc gaaattaata 1140cgactcacta
taggggaatt gtgagcggat aacaattccc catcttagta tattagttaa 1200gtataagaag
gagatataca tatggcagat ctggaggcct gtcatgagtg attacgagcc 1260gttgcgtctg
catgtcccgg agcccaccgg gcgtcctggc tgcaagaccg acttttccta 1320tctgcacctg
tcccccgccg gcgaggtacg caagccgccg gtggatgtcg agcccgccga 1380gaccagcgac
ctggcctaca gcctggtacg tgtgctcgac gacgacggcc acgccgtcgg 1440tccctggaat
ccgcagctca gcaacgaaca actgctgcgc ggcatgcggg cgatgctcaa 1500gacccgcctg
ttcgacgcgc gcatgctcac cgcgcaacgg cagaaaaagc tttccttcta 1560tatgcaatgc
ctcggcgagg aagccatcgc caccgcccac accctggccc tgcgcgacgg 1620cgacatgtgc
tttccgacct atcgccagca aggcatcctg atcacccgcg aatacccgct 1680ggtggacatg
atctgccagc ttctctccaa cgaggccgac ccgctcaagg gccgccagct 1740gccgatcatg
tactcgagca aggaggcagg tttcttctcc atctccggca acctcgccac 1800ccagttcatc
caggcggtcg gctggggcat ggcctcggcg atcaagggcg acacgcgcat 1860cgcctcggcc
tggatcggcg acggcgccac cgccgagtcg gacttccaca ccgccctcac 1920cttcgcccat
gtctaccgcg cgccggtaat cctcaacgtg gtcaacaacc agtgggcgat 1980ctccaccttc
caggccatcg ccggcggcga aggcaccacc ttcgccaacc gtggcgtggg 2040ctgcgggatc
gcctcgctgc gggtcgacgg caatgacttc ctggcggtct acgccgcctc 2100cgagtgggcc
gccgagcgcg cccggcgcaa cctcgggccg agcctgatcg aatgggtcac 2160ctaccgcgcc
ggcccgcact cgacttcgga cgacccgtcc aagtaccgcc ccgccgacga 2220ctggaccaac
ttcccgctgg gcgacccgat cgcccgcctg aagcggcaca tgatcggcct 2280cggcatctgg
tcggaggaac agcacgaagc cacccacaag gccctcgaag ccgaagtact 2340ggccgcgcag
aaacaggcgg agagccatgg caccctgatc gacggccggg tgccgagcgc 2400cgccagcatg
ttcgaggacg tctatgcaga actgccggag cacctgcgcc ggcaacgcca 2460ggagctcggg
gtatgaatgc catgaacccg caacacgaga acgcccagac ggtcaccagc 2520atgaccatga
tccaggcgct gcgctcggcg atggacatca tgctcgagcg cgacgacgac 2580gtggtggtat
tcggccagga cgtcggctac ttcggcggcg tgttccgctg caccgaaggc 2640ctgcagaaga
aatacggcac ctcgcgggtg ttcgatgcgc cgatctccga gagcggcatc 2700atcggcgccg
cggtcggcat gggtgcctac ggcctgcgcc cggtggtgga gatccagttc 2760gccgactacg
tctacccggc ctccgaccag ttgatctccg aggcggcgcg cctgcgctat 2820cgctcggccg
gcgacttcat cgtgccgatg accgtacgca tgccctgtgg cggcggcatc 2880tacggcgggc
aaacgcacag ccagagcccg gaggcgatgt tcacccaggt ctgcggcctg 2940cgcacggtga
tgccgtccaa cccctacgac gccaagggcc tgctgatcgc ctgcatcgag 3000aacgacgacc
cggtgatctt cctcgagccc aagcgcctct acaacggccc gttcgatggc 3060caccacgacc
gcccggtgac gccctggtcc aagcatccgg ccagccaggt gccggacggc 3120tactacaagg
tgccgctgga caaggcggcg atcgtccgcc ccggcgcggc gctgaccgtg 3180ctgacctacg
gcaccatggt ctacgtggcc caggccgcgg ccgacgagac cggcctggac 3240gccgagatca
tcgacctgcg cagcctctgg ccgctggacc tggaaaccat cgtcgcctcg 3300gtgaagaaga
ccggccgctg cgtcatcgcc cacgaggcga cccgcacctg cgggttcggc 3360gccgagctga
tgtcgctggt gcaggagcac tgcttccacc acctggaggc gccgatcgag 3420cgcgtcaccg
gttgggacac cccctacccg catgcccagg agtgggcgta tttccccggc 3480cccgcgcgcg
tcggcgcggc attcaagcgt gtgatggagg tctgaatggg taccctcgag 3540tctggtaaag
aaaccgctgc tgcgaaattt gaacgccagc acatggactc gtctactagc 3600gcagcttaat
taacctaggc tgctgccacc gctgagcaat aactagcata accccttggg 3660gcctctaaac
gggtcttgag gggttttttg ctgaaacctc aggcatttga gaagcacacg 3720gtcacactgc
ttccggtagt caataaaccg gtaaaccagc aatagacata agcggctatt 3780taacgaccct
gccctgaacc gacgaccggg tcatcgtggc cggatcttgc ggcccctcgg 3840cttgaacgaa
ttgttagaca ttatttgccg actaccttgg tgatctcgcc tttcacgtag 3900tggacaaatt
cttccaactg atctgcgcgc gaggccaagc gatcttcttc ttgtccaaga 3960taagcctgtc
tagcttcaag tatgacgggc tgatactggg ccggcaggcg ctccattgcc 4020cagtcggcag
cgacatcctt cggcgcgatt ttgccggtta ctgcgctgta ccaaatgcgg 4080gacaacgtaa
gcactacatt tcgctcatcg ccagcccagt cgggcggcga gttccatagc 4140gttaaggttt
catttagcgc ctcaaataga tcctgttcag gaaccggatc aaagagttcc 4200tccgccgctg
gacctaccaa ggcaacgcta tgttctcttg cttttgtcag caagatagcc 4260agatcaatgt
cgatcgtggc tggctcgaag atacctgcaa gaatgtcatt gcgctgccat 4320tctccaaatt
gcagttcgcg cttagctgga taacgccacg gaatgatgtc gtcgtgcaca 4380acaatggtga
cttctacagc gcggagaatc tcgctctctc caggggaagc cgaagtttcc 4440aaaaggtcgt
tgatcaaagc tcgccgcgtt gtttcatcaa gccttacggt caccgtaacc 4500agcaaatcaa
tatcactgtg tggcttcagg ccgccatcca ctgcggagcc gtacaaatgt 4560acggccagca
acgtcggttc gagatggcgc tcgatgacgc caactacctc tgatagttga 4620gtcgatactt
cggcgatcac cgcttccctc atactcttcc tttttcaata ttattgaagc 4680atttatcagg
gttattgtct catgagcgga tacatatttg aatgtattta gaaaaataaa 4740caaatagcta
gctcactcgg tcgctacgct ccgggcgtga gactgcggcg ggcgctgcgg 4800acacatacaa
agttacccac agattccgtg gataagcagg ggactaacat gtgaggcaaa 4860acagcagggc
cgcgccggtg gcgtttttcc ataggctccg ccctcctgcc agagttcaca 4920taaacagacg
cttttccggt gcatctgtgg gagccgtgag gctcaaccat gaatctgaca 4980gtacgggcga
aacccgacag gacttaaaga tccccaccgt ttccggcggg tcgctccctc 5040ttgcgctctc
ctgttccgac cctgccgttt accggatacc tgttccgcct ttctccctta 5100cgggaagtgt
ggcgctttct catagctcac acactggtat ctcggctcgg tgtaggtcgt 5160tcgctccaag
ctgggctgta agcaagaact ccccgttcag cccgactgct gcgccttatc 5220cggtaactgt
tcacttgagt ccaacccgga aaagcacggt aaaacgccac tggcagcagc 5280cattggtaac
tgggagttcg cagaggattt gtttagctaa acacgcggtt gctcttgaag 5340tgtgcgccaa
agtccggcta cactggaagg acagatttgg ttgctgtgct ctgcgaaagc 5400cagttaccac
ggttaagcag ttccccaact gacttaacct tcgatcaaac cacctcccca 5460ggtggttttt
tcgtttacag ggcaaaagat tacgcgcaga aaaaaaggat ctcaagaaga 5520tcctttgatc
ttttctactg aaccgctcta gatttcagtg caatttatct cttcaaatgt 5580agcacctgaa
gtcagcccca tacgatataa gttgtaattc tcatgttagt catgccccgc 5640gcccaccgga
aggagctgac tgggttgaag gctctcaagg gcatcggtcg agatcccggt 5700gcctaatgag
tgagctaact tacattaatt gcgttgcgct cactgcccgc tttccagtcg 5760ggaaacctgt
cgtgccagct gcattaatga atcggccaac gcgcggggag aggcggtttg 5820cgtattgggc
gccagggtgg tttttctttt caccagtgag acgggcaaca gctgattgcc 5880cttcaccgcc
tggccctgag agagttgcag caagcggtcc acgctggttt gccccagcag 5940gcgaaaatcc
tgtttgatgg tggttaacgg cgggatataa catgagctgt cttcggtatc 6000gtcgtatccc
actaccgaga tgtccgcacc aacgcgcagc ccggactcgg taatggcgcg 6060cattgcgccc
agcgccatct gatcgttggc aaccagcatc gcagtgggaa cgatgccctc 6120attcagcatt
tgcatggttt gttgaaaacc ggacatggca ctccagtcgc cttcccgttc 6180cgctatcggc
tgaatttgat tgcgagtgag atatttatgc cagccagcca gacgcagacg 6240cgccgagaca
gaacttaatg ggcccgctaa cagcgcgatt tgctggtgac ccaatgcgac 6300cagatgctcc
acgcccagtc gcgtaccgtc ttcatgggag aaaataatac tgttgatggg 6360tgtctggtca
gagacatcaa gaaataacgc cggaacatta gtgcaggcag cttccacagc 6420aatggcatcc
tggtcatcca gcggatagtt aatgatcagc ccactgacgc gttgcgcgag 6480aagattgtgc
accgccgctt tacaggcttc gacgccgctt cgttctacca tcgacaccac 6540cacgctggca
cccagttgat cggcgcgaga tttaatcgcc gcgacaattt gcgacggcgc 6600gtgcagggcc
agactggagg tggcaacgcc aatcagcaac gactgtttgc ccgccagttg 6660ttgtgccacg
cggttgggaa tgtaattcag ctccgccatc gccgcttcca ctttttcccg 6720cgttttcgca
gaaacgtggc tggcctggtt caccacgcgg gaaacggtct gataagagac 6780accggcatac
tctgcgacat cgtataacgt tactggtttc acattcacca ccctgaattg 6840actctcttcc
gggcgctatc atgccatacc gcgaaaggtt ttgcgccatt cgatggtgtc 6900cgggatctcg
acgctctccc ttatgcgact cctgcattag gaaattaata cgactcacta
6960208757DNAArtificial SequenceDescription of Artificial Sequence
Synthetic plasmid polynucleotide 20caaggagatg gcgcccaaca gtcccccggc
cacggggcct gccaccatac ccacgccgaa 60acaagcgctc atgagcccga agtggcgagc
ccgatcttcc ccatcggtga tgtcggcgat 120ataggcgcca gcaaccgcac ctgtggcgcc
ggtgatgccg gccacgatgc gtccggcgta 180gaggatcgag atctcgatcc cgcgaaatta
atacgactca ctatagggga attgtgagcg 240gataacaatt cccctctaga aataattttg
tttaacttta agaaggaatt caggagccct 300tatgcaattt aatgaagaac agctattaat
tcaggatatg gcgaaaagtt ttgccaatga 360acagattaaa tctaatgcag cagaatggga
taagcatagc atttttccaa aagacgtttt 420gtcccaaatg gggcaattgg gttttatggg
aatgctggtg agtgagaaat ggggcggatc 480aaatacagga aatttagctt atgtgctggc
acttgaagaa atcgctgccg cagatggtgc 540gacttcaacc attatgagtg tacataattc
tgttggctgt gtacccattg ctaaatttgg 600tacagaggag caaaagcaga aatatctagt
gcctttagca caaggtgaaa tgatcggtgc 660atttgcttta acggaaccac atacaggttc
cgatgccgca gccattaaaa cccgagcaat 720taaacaaggt gatgaatgga ttattaatgg
cgctaaacaa tttataacat caggtcataa 780tgcgggcgtg attattgtat ttgctgtgac
agatccgaat gcagggaaaa aagggctgag 840tgcatttatt gtgccgcgtg aaaccttggg
ttatgaggtg attcgcaccg aagaaaaatt 900gggtttacat gcgtcagata cgtgccaaat
tgctttaacg gatgttcgag tacatcacag 960cttaatgctt ggtcaggaag gtgagggact
aaaaatagca ttgtctaatc tggaaggtgg 1020ccgtattggg attgcagcgc aagccgttgg
tttggcacgt gctgcactag aagaagcgac 1080aaaatatgcc aaagagcgtg tgacctttgg
aaagcctatt tttgagcatc aggcgttagc 1140ctttcgttta gccagtatgg ccacagaaat
tgaagcagca cgacaattgg ttcattacgc 1200agcgcggctt aaagaagctg gaaaaccttg
tttaaatgaa gcatcaatgg cgaaattatt 1260ttcatctgaa atggtcgaac gcgtatgttc
tgctgctttg caaatctttg gtggctatgg 1320ctatttaaaa gactttccca tcgagcgaat
ttatcgtgat gcacgtattt gccagattta 1380tgaaggtaca agtgatattc agcgtttagt
gatagcaaga agcctataac tgacctttgc 1440tgctgtattt ttatcataaa attaagataa
ggattctaaa aatgacattc gcaacaattt 1500tattggaaaa acgtaagggt gtgggcttga
ttacacttaa ccgtccaaaa gcattaaatg 1560ctttaaactc agaattaatt tatgaaataa
atttagcctt agacgattta gaaaatgatc 1620aaacgattgg ttgtatcgtc cttacaggtt
cagaaaaagc ctttgccgca ggtgcggata 1680tcaaagaaat ggcagaatta acttttccaa
atatttattt tgatgatttt tttagtcttg 1740cagatcgtat tgcacagcgt cgtaagcctt
taattgccgc agtgagtggt tatgctttag 1800gtggtggctg tgagttagca ctcatgtgtg
actttattta ttgtgccgac aatgccaagt 1860ttgcactacc agaagtaact ttaggtgtca
ttcctggtat tggtggaaca cagcgtctaa 1920cgcttgcaat aggcaaagcc aaagccatgg
aaatgtgttt gactgcacgg caaatgcagg 1980ctgctgaggc agaacaaagt ggtttggtgg
cacgcgtttt tagtaaagaa gaacttttag 2040aacaaacctt acaggctgcc gaaaaaatag
cggaaaaatc acgggtatct accataatga 2100ttaaagagtc aattaatcga gcttttgaag
tgagtttagc agagggttta cgttttgagc 2160gccgaatgtt ccattcagtt tttgcgacct
tagatcagaa agaaggcatg caagcattta 2220ttgataaacg tccagcccaa tttaaacatc
aataatagga tgaagcgatg actactactg 2280acaatcattt actcattgaa cataaaaacg
ctttaggaac aattatttta aatcgtccag 2340cgagtctgaa cgcgctatct ctagaaatga
ttaatgcgat tcgtcaacaa gttgaggatt 2400ggcaaggtga tgtaaatgtt caggccatat
taattaaatc aaatagtcct aaagcatttt 2460gtgcaggtgg tgatattcgc tatctttatg
aaagttataa aagtggatca gaagagtata 2520aagattattt cattgctgaa tatgagatgc
tcaatagcat tcgaacgtct aaaaaaacag 2580tgattgtttt attggatgga tatgtattgg
gtggtggttt tggtttagca caggcttgtc 2640atatcttggt gagtagtgaa aaatcacgat
tttcaatgcc agaaacagca ataggttttt 2700tcccagatgt tgcagcgact tatttcttat
ctcgtttaga tgatgttggg gtatatttgg 2760cactgactgg tgatcaaatc agtagtagtg
atgcattgta tttagatctg attgattatc 2820atgttccgag tcagaatttt gagcgactag
aaaatgcatt cagccaatca cagaacttag 2880ataaatttca tattcagaag attatttctg
cttatatctc cagccctgtt cagagtgaac 2940tcagtctatg gcttgaagcc attcgtcagc
attttggtct taaaaatgtg caagatatcg 3000aagaaagttt gaaaaatgaa caagatccca
actatcaagt atggacaagt aaagtgttaa 3060atactttgca acaacgttcc tctattgcaa
aaaaaaccag tttaaagtta cagctgctag 3120ggcgtggatg gtcattacag caatgtatgc
gtatcgagcg aaaattacag gatatctggt 3180ttgaacatgg tgatatgatt gagggtgttc
gagcgttgat tattgataaa gataaacaac 3240cgcaatggca gcagcataat gcgactttag
ataatatatt aggccaatta ggttagtcat 3300ttcagactga agggcgagct caattcgaag
cttgaaggta agcctatccc taaccctctc 3360ctcggtctcg attctacgcg taccggtcat
catcaccatc accattgagt ttgatccggc 3420tgctaacaaa gcccgaaagg aagctgagtt
ggctgctgcc accgctgagc aataactagc 3480ataacccctt ggggcctcta aacgggtctt
gaggggtttt ttgctgaaag gaggaactat 3540atccggatat cccgcaagag gcccggcagt
accggcataa ccaagcctat gcctacagca 3600tccagggtga cggtgccgag gatgacgatg
agcgcattgt tagatttcat acacggtgcc 3660tgactgcgtt agcaatttaa ctgtgataaa
ctaccgcatt aaagcttatc gatgataagc 3720tgtcaaacat gagaattaat tcttgaagac
gaaagggcct cgtgatacgc ctatttttat 3780aggttaatgt catgataata atggtttctt
agacgtcagg tggcactttt cggggaaatg 3840tgcgcggaac ccctatttgt ttatttttct
aaatacattc aaatatgtat ccgctcatga 3900gacaataacc ctgataaatg cttcaataat
attgaaaaag gaagagtatg agtattcaac 3960atttccgtgt cgcccttatt cccttttttg
cggcattttg ccttcctgtt tttgctcacc 4020cagaaacgct ggtgaaagta aaagatgctg
aagatcagtt gggtgcacga gtgggttaca 4080tcgaactgga tctcaacagc ggtaagatcc
ttgagagttt tcgccccgaa gaacgttttc 4140caatgatgag cacttttaaa gttctgctat
gtggcgcggt attatcccgt gttgacgccg 4200ggcaagagca actcggtcgc cgcatacact
attctcagaa tgacttggtt gagtactcac 4260cagtcacaga aaagcatctt acggatggca
tgacagtaag agaattatgc agtgctgcca 4320taaccatgag tgataacact gcggccaact
tacttctgac aacgatcgga ggaccgaagg 4380agctaaccgc ttttttgcac aacatggggg
atcatgtaac tcgccttgat cgttgggaac 4440cggagctgaa tgaagccata ccaaacgacg
agcgtgacac cacgatgcct gcagcaatgg 4500caacaacgtt gcgcaaacta ttaactggcg
aactacttac tctagcttcc cggcaacaat 4560taatagactg gatggaggcg gataaagttg
caggaccact tctgcgctcg gcccttccgg 4620ctggctggtt tattgctgat aaatctggag
ccggtgagcg tgggtctcgc ggtatcattg 4680cagcactggg gccagatggt aagccctccc
gtatcgtagt tatctacacg acggggagtc 4740aggcaactat ggatgaacga aatagacaga
tcgctgagat aggtgcctca ctgattaagc 4800attggtaact gtcagaccaa gtttactcat
atatacttta gattgattta aaacttcatt 4860tttaatttaa aaggatctag gtgaagatcc
tttttgataa tctcatgacc aaaatccctt 4920aacgtgagtt ttcgttccac tgagcgtcag
accccgtaga aaagatcaaa ggatcttctt 4980gagatccttt ttttctgcgc gtaatctgct
gcttgcaaac aaaaaaacca ccgctaccag 5040cggtggtttg tttgccggat caagagctac
caactctttt tccgaaggta actggcttca 5100gcagagcgca gataccaaat actgtccttc
tagtgtagcc gtagttaggc caccacttca 5160agaactctgt agcaccgcct acatacctcg
ctctgctaat cctgttacca gtggctgctg 5220ccagtggcga taagtcgtgt cttaccgggt
tggactcaag acgatagtta ccggataagg 5280cgcagcggtc gggctgaacg gggggttcgt
gcacacagcc cagcttggag cgaacgacct 5340acaccgaact gagataccta cagcgtgagc
tatgagaaag cgccacgctt cccgaaggga 5400gaaaggcgga caggtatccg gtaagcggca
gggtcggaac aggagagcgc acgagggagc 5460ttccaggggg aaacgcctgg tatctttata
gtcctgtcgg gtttcgccac ctctgacttg 5520agcgtcgatt tttgtgatgc tcgtcagggg
ggcggagcct atggaaaaac gccagcaacg 5580cggccttttt acggttcctg gccttttgct
ggccttttgc tcacatgttc tttcctgcgt 5640tatcccctga ttctgtggat aaccgtatta
ccgcctttga gtgagctgat accgctcgcc 5700gcagccgaac gaccgagcgc agcgagtcag
tgagcgagga agcggaagag cgcctgatgc 5760ggtattttct ccttacgcat ctgtgcggta
tttcacaccg caatggtgca ctctcagtac 5820aatctgctct gatgccgcat agttaagcca
gtatacactc cgctatcgct acgtgactgg 5880gtcatggctg cgccccgaca cccgccaaca
cccgctgacg cgccctgacg ggcttgtctg 5940ctcccggcat ccgcttacag acaagctgtg
accgtctccg ggagctgcat gtgtcagagg 6000ttttcaccgt catcaccgaa acgcgcgagg
cagctgcggt aaagctcatc agcgtggtcg 6060tgaagcgatt cacagatgtc tgcctgttca
tccgcgtcca gctcgttgag tttctccaga 6120agcgttaatg tctggcttct gataaagcgg
gccatgttaa gggcggtttt ttcctgtttg 6180gtcactgatg cctccgtgta agggggattt
ctgttcatgg gggtaatgat accgatgaaa 6240cgagagagga tgctcacgat acgggttact
gatgatgaac atgcccggtt actggaacgt 6300tgtgagggta aacaactggc ggtatggatg
cggcgggacc agagaaaaat cactcagggt 6360caatgccagc gcttcgttaa tacagatgta
ggtgttccac agggtagcca gcagcatcct 6420gcgatgcaga tccggaacat aatggtgcag
ggcgctgact tccgcgtttc cagactttac 6480gaaacacgga aaccgaagac cattcatgtt
gttgctcagg tcgcagacgt tttgcagcag 6540cagtcgcttc acgttcgctc gcgtatcggt
gattcattct gctaaccagt aaggcaaccc 6600cgccagccta gccgggtcct caacgacagg
agcacgatca tgcgcacccg tggccaggac 6660ccaacgctgc ccgagatgcg ccgcgtgcgg
ctgctggaga tggcggacgc gatggatatg 6720ttctgccaag ggttggtttg cgcattcaca
gttctccgca agaattgatt ggctccaatt 6780cttggagtgg tgaatccgtt agcgaggtgc
cgccggcttc cattcaggtc gaggtggccc 6840ggctccatgc accgcgacgc aacgcgggga
ggcagacaag gtatagggcg gcgcctacaa 6900tccatgccaa cccgttccat gtgctcgccg
aggcggcata aatcgccgtg acgatcagcg 6960gtccaatgat cgaagttagg ctggtaagag
ccgcgagcga tccttgaagc tgtccctgat 7020ggtcgtcatc tacctgcctg gacagcatgg
cctgcaacgc gggcatcccg atgccgccgg 7080aagcgagaag aatcataatg gggaaggcca
tccagcctcg cgtcgcgaac gccagcaaga 7140cgtagcccag cgcgtcggcc gccatgccgg
cgataatggc ctgcttctcg ccgaaacgtt 7200tggtggcggg accagtgacg aaggcttgag
cgagggcgtg caagattccg aataccgcaa 7260gcgacaggcc gatcatcgtc gcgctccagc
gaaagcggtc ctcgccgaaa atgacccaga 7320gcgctgccgg cacctgtcct acgagttgca
tgataaagaa gacagtcata agtgcggcga 7380cgatagtcat gccccgcgcc caccggaagg
agctgactgg gttgaaggct ctcaagggca 7440tcggtcgaga tcccggtgcc taatgagtga
gctaacttac attaattgcg ttgcgctcac 7500tgcccgcttt ccagtcggga aacctgtcgt
gccagctgca ttaatgaatc ggccaacgcg 7560cggggagagg cggtttgcgt attgggcgcc
agggtggttt ttcttttcac cagtgagacg 7620ggcaacagct gattgccctt caccgcctgg
ccctgagaga gttgcagcaa gcggtccacg 7680ctggtttgcc ccagcaggcg aaaatcctgt
ttgatggtgg ttaacggcgg gatataacat 7740gagctgtctt cggtatcgtc gtatcccact
accgagatat ccgcaccaac gcgcagcccg 7800gactcggtaa tggcgcgcat tgcgcccagc
gccatctgat cgttggcaac cagcatcgca 7860gtgggaacga tgccctcatt cagcatttgc
atggtttgtt gaaaaccgga catggcactc 7920cagtcgcctt cccgttccgc tatcggctga
atttgattgc gagtgagata tttatgccag 7980ccagccagac gcagacgcgc cgagacagaa
cttaatgggc ccgctaacag cgcgatttgc 8040tggtgaccca atgcgaccag atgctccacg
cccagtcgcg taccgtcttc atgggagaaa 8100ataatactgt tgatgggtgt ctggtcagag
acatcaagaa ataacgccgg aacattagtg 8160caggcagctt ccacagcaat ggcatcctgg
tcatccagcg gatagttaat gatcagccca 8220ctgacgcgtt gcgcgagaag attgtgcacc
gccgctttac aggcttcgac gccgcttcgt 8280tctaccatcg acaccaccac gctggcaccc
agttgatcgg cgcgagattt aatcgccgcg 8340acaatttgcg acggcgcgtg cagggccaga
ctggaggtgg caacgccaat cagcaacgac 8400tgtttgcccg ccagttgttg tgccacgcgg
ttgggaatgt aattcagctc cgccatcgcc 8460gcttccactt tttcccgcgt tttcgcagaa
acgtggctgg cctggttcac cacgcgggaa 8520acggtctgat aagagacacc ggcatactct
gcgacatcgt ataacgttac tggtttcaca 8580ttcaccaccc tgaattgact ctcttccggg
cgctatcatg ccataccgcg aaaggttttg 8640cgccattcga tggtgtccgg gatctcgacg
ctctccctta tgcgactcct gcattaggaa 8700gcagcccagt agtaggttga ggccgttgag
caccgccgcc gcaaggaatg gtgcatg 87572128DNAArtificial
SequenceDescription of Artificial Sequence Synthetic primer
21attatcccat ggggagaaca ttaaaagc
282226DNAArtificial SequenceDescription of Artificial Sequence Synthetic
primer 22cgggatcctt acttttcaat atatcc
26
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