Compositions and Methods for Oxygenation of Nucleic Acids Containing 5-Methylpyrimidine

Abstract

5-methylpyrimidine oxygenases and their use in the modification of nucleic acids are described.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] The entire disclosure of each of the following patent applications is hereby incorporated by reference into the present application: U.S. 61/611,295, filed Mar. 15, 2012; U.S. Application No. 61/722,968, filed Nov. 6, 2012; U.S. Application No. 61/723,427, filed Nov. 7, 2012; U.S. Application No. 61/724,041, filed Nov. 8, 2012; U.S. application Ser. No. 13/804,804, filed Mar. 14, 2013; U.S. application Ser. No. 13/826,395, filed Mar. 14, 2013. Also incorporated by reference in its entirety is the following application filed on the same day as the present application: Attorney Docket No. NEB-354-US, "Methods and Compositions for Discrimination Between Cytosine and Modifications Thereof, and for Methylome Analysis."

BACKGROUND

[0002] 5-methylcytosine (5-mC) has been linked to gene expression and its distribution in the genome plays an important role in epigenetics. In 2009, two groups independently discovered that an oxidized form of 5-mC, 5-hydroxymethylcytosine (5-hmC), exists in human and mouse DNA, and is especially enriched in the neuronal tissues as well as embryonic stem cells. Three enzymes named TET1/2/3 have been shown in human and mouse to be responsible for oxidizing 5-mC to 5-hmC. TET enzymes belong to the broad family of Fe(II)/2-oxo-glutarate-dependent (2OGFE) oxygenases, which use 2-oxo-glutarate (2OG), as co-substrate, and ferrous ion (Fe(II)) as cofactor. After additional biochemical studies, it was discovered that these enzymes could oxidize 5-mC to generate oxidation products identified as 5-hmC, 5-formylcytosine (5-fC) and 5-carboxycytosine (5-caC). Finally, 5-caC is believed to be excised via the action of DNA glycosylases and replaced by the unmodified cytosine. The TET enzymes are very large proteins and hence it has been problematic to make these proteins in recombinant form and in sufficient quantities to use as a research reagent.

[0003] In order to identify the impact of the epigenome on phenotype, it is desirable to map the position of modified nucleotides and to understand when and where the various modifications arise. Sodium bisulfite sequencing is the predominant method for mapping modified cytosine in the genome. Unfortunately, this technique does not discriminate between 5-mC and 5-hmC. Different methods are required to distinguish 5-mC from 5-hmC and its oxidation products.

SUMMARY

[0004] Although Neigleria gruberi has not been previously reported to contain 5-mC or 5-hmC, the present inventors have surprisingly discovered that a protein from N. gruberi can be used in vitro to convert 5-mC to oxidized cytosines. That protein can be purified from natural sources or produced recombinantly, optionally as a fusion protein with another amino acid sequence to facilitate its purification or use.

[0005] Accordingly, in one aspect the invention provides a fusion protein in which a binding domain is fused to a recombinant 5-methylpyrimidine oxygenase (mYOX1) having a size less than 600 amino acids and having a catalytic domain having 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. In certain embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to amino acids 209-296, 160-297, 154-304 or 1-321 of the amino acid sequence of SEQ ID NO:2 (mYOX1), and/or with the corresponding amino acids of any one of SEQ ID NOs:3-9 as aligned with SEQ ID NO:2 in FIG. 2B, optionally while retaining 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. In other embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to the entire length of SEQ ID NO:2, 3, 4, 5, 6, 7, 8, or 9. The binding domain is capable of recognizing and binding to another molecule. Thus, in some embodiments the binding domain is a histidine tag ("His-tag"), a maltose-binding protein, a chitin-binding domain, or a DNA-binding domain, which may include a zinc finger and/or a transcription activator-like (TAL) effector domain. The fusion protein can be used as a mYOX1 (such as a 5-mC oxygenase or a thymine hydroxylase) in single- or double-stranded DNA or in RNA, typically at a pH of about 6 (generally between 5.5 and 6.5) to about 8, and, in some embodiments, at a pH of about 6 to about pH 7.5.

[0006] In another aspect, the invention provides buffered compositions containing a purified mYOX1 having a size less than 600 amino acids and having a catalytic domain having 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. In certain embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to amino acids 209-296, 160-297, 154-304 or 1-321 of the amino acid sequence of SEQ ID NO:2, and/or with the corresponding amino acids of any one of SEQ ID NOs:3-9 as aligned with SEQ ID NO:2 in FIG. 2B, optionally while retaining 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. In other embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to the entire length of SEQ ID NO:2, 3, 4, 5, 6, 7, 8, or 9. In various embodiments, the composition contains glycerol; and/or contains Fe(II), as cofactor, and α-ketoglutarate, as co-substrate, for the enzyme. In some of these embodiments, the composition does not contain ATP, which can interfere with subsequent oxidation of hydroxymethylated nucleotides; in other embodiments, the composition does contain ATP (e.g. to inhibit further oxidation). The composition is optionally at a pH from about 6 to about 8. In certain embodiments, the pH is about 6, or is from about 6 to about 7.5.

[0007] The buffered compositions can be used to generate a variety of oxidation products of 5-mC, including 5-hmC, 5-fC, and 5-caC. The distribution of oxidation products can be varied by varying the pH of the reaction buffer. Accordingly, in various embodiments the pH of the buffered composition is about 6; about 6.0 to about 6.5; about 6.0 to about 7.0; about 6.0 to about 7.5; about 6.0 to about 8.0; about 6.5 to about 7.0; about 6.5 to about 7.5; about 6.5 to about 8.0; about 7.0 to about 8.0; or about 7.5 to about 8.0.

[0008] In some embodiments, the buffered compositions also include a nucleic acid, such as single- or double-stranded DNA that may include 5-mC (as a substrate for the enzyme) and/or one or more of 5-hmC, 5-fC, or 5-caC (naturally-occurring, and/or resulting from the activity of the enzyme).

[0009] The invention also provides kits for modifying nucleic acids. The kits include a purified mYOX1 having a size less than 600 amino acids and having a catalytic domain having 90% or 100% identity with the amino acid sequence of SEQ ID NO:1, or any one of the buffered compositions or fusion proteins described above, together with a separate reaction buffer. In certain embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to amino acids 209-296, 160-297, 154-304 or 1-321 of the amino acid sequence of SEQ ID NO:2, optionally while retaining 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. The reaction buffer has a pH typically from about 6 to about 8, and may contain contains Fe(II) and/or α-ketoglutarate. In various embodiments, the pH of the reaction buffer is about 6; about 6.0 to about 6.5; about 6.0 to about 7.0; about 6.0 to about 7.5; about 6.0 to about 8.0; about 6.5 to about 7.0; about 6.5 to about 7.5; about 6.5 to about 8.0; about 7.0 to about 8.0; or about 7.5 to about 8.0. The kit may also include a nucleic acid such as single- or double-stranded DNA that may include one or more 5-mC residues. Also, or alternatively, the kit may include: a reducing agent, such as sodium borohydride, or an additive, such as cobalt chloride; a β-glycosyltransferase (BGT) and UDP-glucose and/or UDP-glucosamine; a DNA glycosylase such as thymine DNA glycosylase; and/or an endonuclease, such as an endonuclease that cleaves DNA containing 5-hmC more efficiently than it cleaves DNA containing β-glucosyl-oxy-5-methylcytosine (5-ghmC) (e.g. AbaSI).

[0010] The invention also provides kits for detecting the 5-mC in double-stranded or single-stranded DNA or RNA by sequencing, e.g., single-molecular sequencing such as Pacific Biosciences platform. The kits include a purified mYOX1 having a size less than 600 amino acids and having a catalytic domain having 90% or 100% identity with the amino acid sequence of SEQ ID NO:1, or any one of the buffered compositions or fusion proteins described above, together with a separate reaction buffer. In certain embodiments, the mYOX1 has an amino acid sequence with at least 90% identity (or more, such as at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity) to amino acids 209-296, 160-297, 154-304 or 1-321 of the amino acid sequence of SEQ ID NO:2, optionally while retaining 90% or 100% identity with the amino acid sequence of SEQ ID NO:1. The reaction buffer has a pH typically from about 6 to about 8, and may contain contains Fe(II) and/or α-ketoglutarate. In various embodiments, the pH of the reaction buffer is about 6; about 6.0 to about 6.5; about 6.0 to about 7.0; about 6.0 to about 7.5; about 6.0 to about 8.0; about 6.5 to about 7.0; about 6.5 to about 7.5; about 6.5 to about 8.0; about 7.0 to about 8.0; or about 7.5 to about 8.0. The kit may contain other DNA/RNA repair enzymes for the DNA or RNA to be used in the sequencing platforms.

[0011] In another aspect, the invention provides methods for differentiating a 5-mC from 5-hmC in a genome or genome fragment. In one embodiment, the method includes: reacting the isolated genome or genome fragment containing 5-mC and 5-hmC with UDP-glucose or UDP-glucosamine, a glycosyltransferase for transferring glucose or glucosamine to the 5-hmC, and one of the previously described fusion proteins or buffered compositions; cleaving the glucosylated template with a modification-dependent endonuclease that recognizes at least one of the modified nucleotides; and differentiating the 5-mC from the 5-hmC by an altered cleavage pattern. In another embodiment, the method includes: reacting the isolated genome or genome fragment containing 5-mC and 5-hmC with UDP-glucosamine and a glycosyltransferase for transferring glucosamine to the 5-hmC; subsequently reacting the isolated genome or genome fragment with one of the previously described fusion proteins or buffered compositions and optionally with a reducing agent; cleaving the template with a modification-dependent endonuclease that is capable of selectively cleaving a 5-hmC and not a 5-ghmC; and differentiating the 5-mC from one or more of its oxidation products by an altered cleavage pattern. In each of these embodiments, the modification-dependent endonuclease is optionally AbaSI.

[0012] The invention also provides methods of modifying a 5-mC oxygenase by introducing random or targeted mutations and changing the specificity of the enzyme so as to exclusively oxidize 5-mC to 5-hmC.

BRIEF DESCRIPTION OF THE FIGURES

[0013] FIG. 1 shows a phylogram of mYOX1 in Naegleria gruberi and TET proteins based on the ClustalW multiple sequence alignment. TET1_hs_C, human TET1 truncated C-terminus; TET1_mm_C, mouse TET1 truncated C-terminus; TET2_hs_C, human TET2 truncated C-terminus; TET2_mm_C, mouse TET2 truncated C-terminus; TET3_hs_C, human TET3 truncated C-terminus; TET3_mm_C, mouse TET3 truncated C-terminus.

[0014] FIG. 2A-B shows eight mYOX proteins in Naegleria gruberi and their alignments. This family of problems has a consensus sequence (R/K)X₄HXDX₁₂GX.sub.18-30DX₁₀HXVX₇-72RX₅FA (SEQ ID NO:1).

[0015] FIG. 2A shows the conserved domain structure of the 8 mYOX proteins anchored by the 2OGFE catalytic domain. An additional domain, a CHROMO domain, was detected in one of the proteins.

[0016] FIG. 2B shows multiple sequence alignment of the 2OGFE catalytic domain sequences in mYOX proteins. Alignment was performed by the PROMALS program (http://prodata.swmed.edu/promals/promals.php).

[0017] FIG. 3 shows a single band of purified recombinant mYOX1 having a molecular weight of 37,321 Dalton on an SDS-PAGE.

[0018] FIG. 4A-C shows the activity of mYOX1. FIG. 4A shows the activity on double-stranded DNA with 24 fully-methylated CpG sites ("24× oligo"). FIG. 4B shows the activity on plasmid DNA ("pTXB1-M.Sss1"). FIG. 4C shows the activity on genomic DNA ("IMR90").

[0019] All substrate DNA contained 5-mC. The generation of 5-hmC, 5-fC and 5-caC was monitored by liquid chromatography. The generation of 5-hmC was dependent on mYOX1, since no 5-hmC was detected in the absence of the enzyme. In addition, mYOX1 was able to convert thymine to 5-hmU, 5-fU and 5-caU (data not shown). These results indicate that mYOX1 is an active 5-mC oxygenase and thymine hydroxylase.

[0020] FIG. 5 shows methods for mapping methylome and hydroxymethylome using the DNA modification-dependent restriction endonucleases.

DETAILED DESCRIPTION OF EMBODIMENTS

[0021] In general and in at least one aspect, a novel family of enzymes is described. Generally, these enzymes can be described as mYOXs, or, more specifically, 5-mC oxygenases that can use 2OG, as co-substrate, and ferrous ion (Fe(II)), as cofactor. This novel family, whose members are referred to in this application as mYOXs, is distantly related to the TET proteins, as shown in the phylogram of FIG. 1, sharing about 15% sequence identity with them. Compared to TET proteins, mYOXs have several advantages as reagents for oxygenating 5-mC. With sizes in the range of 174-583aa, mYOXs are substantially smaller than enzymes of the TET family (which are ˜1600-2000aa), facilitating their recombinant production. Their small size renders these enzymes suitable as components in fusion proteins with, for example, DNA binding domains such as zinc fingers, and/or one or more additional enzymatic domains such as a glycosylase to promote the eventual excision of the modified cytosine. Moreover, in contrast to TET proteins, mYOXs operate more efficiently at pH 7.5 or less (e.g. at about pH 6), and do not require ATP which is significant because it reduces the possibility of side reactions, for example, phosphorylation, and permits use of the enzymes in conjunction with PCR amplification which is inhibited by ATP. An additional advantage of mYOX1 over TET proteins as research reagents includes its improved catalytic efficiency. For example, stoichiometrically fewer enzyme molecules are needed to oxidize 5-mCs when using mYOX1 rather than a TET enzyme.

[0022] One of the advantages of oxidizing 5-mC in vitro is the ability to add chemical or fluorescent labels onto DNA, which can be further coupled to sequencing technologies and map the DNA epigenomes.

[0023] mYOXs can be cloned and purified from Naegleria gruberi, a free-living single-cell protist as described in Example 1. Host cells suitable for expression include E. coli, yeast and insect cell systems producing greater than 10 μg/l, 20 μg/l, 30 μg/l, 50 μg/l, 70 μg/l, 100 μg/l, 200 μg/l, 300 μg/l, 400 μg/l, 500 μg/l and as much as 10 mg/liter of culture. A unit amount of mYOX1 is able to convert 1 pmol of 5-mC on DNA in 30 minutes at 34° C. in 1× mYOX1 reaction buffer at pH 6.0 (unit definition).

[0024] Exemplary mYOX protein sequences are provided in the following table:

TABLE-US-00001 SEQ ID Name Accession # NO: SEQUENCE mYOX1 XP_002667965.1 2 MTTFKQQTIKEKETKRKYCIKGTTANLTQT HPNGPVCVNRGEEVANTTTLLDSGGGINK KSLLQNLLSKCKTTFQQSFTNANITLKDEK WLKNVRTAYFVCDHDGSVELAYLPNVLPK ELVEEFTEKFESIQTGRKKDTGYSGILDNS MPFNYVTADLSQELGQYLSEIVNPQINYYIS KLLTCVSSRTINYLVSLNDSYYALNNCLYPS TAFNSLKPSNDGHRIRKPHKDNLDITPSSL FYFGNFQNTEGYLELTDKNCKVFVQPGDVL FFKGNEYKHVVANITSGWRIGLVYFAHKG SKTKPYYEDTQKNSLKIHKETK mYOX6 XP_002674105.1 3 MPMNYITSDLKTQLGEYLIGIVNPMLDETIT AALEILSPRTINYLTSLPHPYHILNNCIYPST AFNYLEPQIEKHRIKNAHKDTRDATPSVLF YLGDYDEKEGYLEFPEQNCKVFVKPGDLLL FKGNKYKHQVAPITSGTRLGLVYFAHKACK VMDFYDDYQKESLNKHKQQNQ mYOX4 XP_002676528.1 4 MSINTTFNQKTTQSGEPPMMMRMTNSSTP PLTPKNCLPIFVYNDYGKLIREEQQQPTDII TNNNNSMMRSMPTTNRWETNPQTPLSVS PFQPLLPIPNFSHAFIVGNLPPSVSVRRKNR KMSEKPKNNSAPSKIMHQLELSVLNNQRR IAPKGPLADISNIQLPQQESTNKSNNTTPK KPRIRQLMLTTPLRESLQSNQSARSKYIDE EANNYSINDSPETTIIKTSNTKDSEHKAAM ATNLGLSTDDFECKPFETTTLPSVIDKNYLV VDKEGCTQLALLPN HIPTSVCKLIEVKCRK VSNLRHALKIQKASFYVNWWTKSQPMGY MCKDNESEIGKVVNEIAELLSDHCRNLLR MCNERVYKKISELKEDKFFAPCICFNILEHD LESRITKFHHDKMDYGVSVLFYFGDYSRG NLNVLDAGSSSTIVTRPGDAVILRGNYYKH SVQNIEPGNNKARYSIVFFAHSTHFLKKKY ELSPAAAKKAFLVDNPDFVSIKKRKQASSS SDVSVKKSKKSTEDNVEFIQTHTYLGNGY KSGHKNYQYYVKFNNSDQKEWKSYESLPK QAVASYWVKFKKLKSLSNQ mYOX7 XP_002668594.1 5 MLEAQHHKLTIYTGMWGHMKPCVFIAADN CNKSGETIVENLLFKLGKIGSKLMEILSPFT MNFLSSLDPEIFLNHDLFPISATNFMIPGNK HRILKPHKDNQDVGLCIIFYFGNYNAPLEF VNKGSVFNTERGDVLLMRGSHFRHVVKPV DNGLLEHVHDPMRISVVLFAHKSLKMNPS YFLNAGSALKAHDEDFPEKAKKRKKKRK mYOX8 XP_002676954.1 6 MFLRNILPENTTTEVTNILDKINQRRSKENY YIGSWGKSSSFLFKTNDTIFNELSSQFIKII NLLKNYVLEILKFGNNKMRKFLEKYNSSDF LSIYPTVCFNFLDKSVDENRILHIHPDKEDT GTSLIFYFGKFKGGAISFPELNFKLMVQSA DVLLFDGKNNLHAVESLHGKDDVRYSVVF FAHKADLGKTSYPMNRGEVMKGIKNKINN mYOX5 XP_002668409.1 7 MDIGIDWRGTHFRHKNHLVKEEVCDRTN WIVLCPNGQVDIAFFPNAIPEELCLEMETV VANSDVDILSCKKAIIDGSWTRYGNGIYPV KTITTNQSILLHELNDKCGPFVLDKLKHINK NMFNKLDNINEDIKNYKIFAKYPTLALNVS HNENYNISKKPYRKHTDGNDIGLGVLTYFG SEIIEGGNLIIHIENLKVFNFPIQRRDLVFLN SKFYAHQVTKVTSGIRFGLVYFAGEAHFRV RNNDDFLPALPFNANDKELREERSKKGRK SMNEYKKRFLKKYLREKKKINKKRVKCKNK LK mYOX2 XP_002682154.1 8 MGPLHVSQHDKKKPKHRRRKKQFLKAQAL TRVCWENEKSIDESGKTRVYKMIKEWEFL KGNNIQSNEPILSVYGVNDTIPKEISSNTII VTKEGMVEMALLKSVLPPSLLEECTQLCRE MSEWLATEKDIDKGSFFSGWWTMNMPM GYKCADSFRFELVDTKVKQIQALLHDTFQH ILELANPKLFAKLSKLTERGQTPVVCFNMIP TRNESVKEKFQGSYKSTDKVNRPKTNHRD RNDMGISAMFYMGKFGGGSLQLIRVNEHT PKTLVHIQAGDVVLLRAN KYRHAVSPTRPQ SFPLANSSQTEVDDVKICENSSPTLNNPQA DDNTPTLINTCPKQEPTDGDNPVQSSKEP SNDYEQKRFSFIFFAHRSHFKHSKVYCGM GQRQALNAFKADHPYYQSQRMKKKLGDD CLDQSLILTEKRKPIKRNYALFNECGDDKQ EESDEEEYQQYEPKPTTEEYTIKVIVDHEKV FKGSDQSRKSYLYHIQWLGYPDETWEPYE HLDDCQVFEDYLKHHNISLFDEEEEDRKV DDSMLLPAWMHEDESLFEALLPIICCSTDN PRHHLDDVPPFDFNY mYOX3 XP_002668005.1 9 MTEIVELSNIEPKDQKQAIIGGTWNRYGNS IEIVAGISDENNTLLDNLTNCCESFVLDKL WHLNRSMYNKLDTIEEKIKNFKTYAKYPSL ALNLLCKENYNGKVKPYRKHIDPNNNGMD VLMFFGKTFEGGNLIVSYHYTNIDFRMFTLP IQSGDLVFLNSRIYHHKVTKVTSGVRCGLV FFAGLDHFSVRKANYKKVKKEEYQKNMDD KLLALPFQQKDKDLRIERTKTGRKEIKQFH KNLQNNLPNKKRKK

[0025] FIG. 2A-B depicts the common structure among these 8 mYOX proteins, including a conserved domain structure 9 (see panel A) and conserved sequences in that conserved domain as revealed by a multiple sequence alignment (see panel B). These 8 proteins share a common consensus sequence: (R/K)X₄HXDX₁₂GX.sub.18-30DX₁₀HXVX₇-72RX.sub- .5FA (SEQ ID NO:1).

[0026] Biochemical assays for characterization of these enzymes includes: non-quantitative assays, e.g., dot-blot assay using product-specific antibodies, thin-layer chromatography, and quantitative assays, e.g., LC/MS, radioactive assay etc.

[0027] mYOX enzymes may oxidize 5-mC through intermediate product forms to 5-caC. Mutants of these enzymes can be assayed for significant bias toward one oxidized form over another for example, a significant bias for conversion of 5-mC to 5-hmC or 5-mC to 5-fC or 5-caC. This allows direct detection of a single oxidation form and also a temporal means of tracking change in the oxidation state of modified nucleotides in the genome and correlation of these states and their changes to phenotypic change.

[0028] Additional mutants may include those that only oxidize 5-mC, or 5-hmC, or 5-fC, but not other modified forms of cytosine. For example, a mutant may oxidize 5-hmC to 5-fC or 5-caC, but will not work on 5-mC. These mutants may enable a variety of in vitro epigenomic mapping techniques.

[0029] Mutants can be engineered using standard techniques such as rational design by site-directed mutagenesis based on enzyme 3D structures and screening/selection methods in large random mutant libraries.

[0030] Embodiments of the invention include uses of mYOXs for mapping of both methylome and hydroxymethylome. For example, differentiation processes in eukaryotic organisms can be studied using N. gruberi as a model system. N. gruberi is a single-cell protist that can differentiate from an ameoba form to a flagella form in a synchronous manner. It thus forms a model system to study dynamic methylome/hydroxymethylome changes that contribute to the gene/pathway regulation during differentiation.

[0031] In one embodiment, the 5-mC in the genomic DNA can be converted to 5-hmC using an mYOX such as mYOX1 or other member of the mYOX family. Reducing agents, such as NaBH4, can be used in the reaction to ensure that any oxidation products in the form of 5-fC or 5-caC or naturally occurring instances of the same are converted to 5-hmC.

[0032] Any chemical or enzyme capable of promoting the reduction of 5-fC or 5-caC to 5-hmC can be used for that purpose. Many water-soluble metal or metalloid hydrides are able to reduce aldehydes and/or carboxylic acids to alcohols. Examples of such reducing agents are sodium borohydride and related compounds where from 1 to 3 of the hydrogens are replaced by other moieties, such as cyano and alkoxy containing up to about 5 carbon atoms. Examples of substituted borohydrides, all of which are sodium, potassium, or lithium salts, include cyanoborohydride, dicyanoborohydride, methoxyborohydride, dimethoxyborohydride, trimethoxyborohydride, ethoxyborohydride, diethoxyborohydride, triethoxyborohydride, propoxyborohydride, dipropoxyborohydride, tripropoxyborohydride, butoxyborohydride, dibutoxyborohydride, tributoxyborohydride, and so forth. Examples of other water-soluble metal hydrides include lithium borohydride, potassium borohydride, zinc borohydride, aluminum borohydride, zirconium borohydride, beryllium borohydride, and sodium bis(2-methoxyethoxy)aluminium hydride. Sodium borohydride can also be used in combination with a metal halide, such as cobalt(II), nickel(II), copper(II), zinc(II), cadmium (II), calcium (II), magnesium(II), aluminum(III), titanium (IV), hafnium(IV), or rhodium(III), each of which can be provided as a chloride, bromide, iodide, or fluoride salt. Alternatively, sodium borohydride can be used in combination with iodine, bromine, boron trifluoride diethyl etherate, trifluoroacetic acid, catechol-trifluoroacetic acid, sulfuric acid, or diglyme. Particular reducing strategies include the combination of potassium borohydride with lithium chloride, zinc chloride, magnesium chloride, or hafnium chloride; or the combination of lithium borohydride and chlorotrimethylsilane. Other reducing strategies include the use of borane, borane dimethyl sulfide complex, borane tetrahydrofuran complex, borane-ammonia complex, borane morpholine complex, borane dimethylamine complex, borane trimethylamine complex, borane N,N-diisopropylethylamine complex, borane pyridine complex, 2-picoline borane complex, borane 4-methylmorpholine complex, borane tert-butylamine complex, borane triphenylphosphine complex, borane N,N-diethylaniline complex, borane di(tert-butyl)phosphine complex, borane diphenylphosphine complex, borane ethylenediamine complex, or lithium ammonia borane. Alternative reducing strategies include the reduction of carboxylic acids via the formation of hydroxybenzotriazole esters, carboxy methyleniminium chlorides, carbonates, O-acylisoureas, acyl fluorides, cyanurates, mixed anhydrides, arylboronic anhydrides, acyl imidazolide, acyl azides, or N-acyl benzotriazoles, followed by reaction with sodium borohydride to give the corresponding alcohols.

[0033] Chemical groups, e.g., sugars such as glucose, can be added onto 5-hmC using a glycosyltransferase such as an α-glucosyltransferase (AGT) or a BGT. Useful glycosyltransferases can accept a nucleobase in a nucleic acid as a substrate. Exemplary BGT enzymes are found in bacteriophage, such as T4. The T4 BGT show little DNA sequence specificity, suggesting a mechanism of non-specific DNA binding combined with specific 5-hmC recognition.

[0034] Variants of the T4 BGT can be used. For example, the structure of T4 BGT and the identities of key residues in the enzyme are well understood, facilitating the construction of forms of the protein incorporating one or more amino acid deletions or substitutions. T4 BGT is a monomer comprising 351 amino acid residues and belongs to the α/β protein class. It is composed of two non-identical domains, both similar in topology to Rossmann nucleotide-binding folds, separated by a deep central cleft which forms the UDP-Glc binding site. Amino acids participating in the interaction with UDP include Ile238 (interactions with N3 and O4 of the base); Glu272 (interactions with O2' and O3' of the ribose); Ser189 (interacting with O11 of the α-phosphate); Arg191 (interacting with O12 of the α-phosphate); Arg269 (interacting with O6 of the α-phosphate and O22 of the β-phosphate); and Arg195 (interacting with O21 and O22 of the β-phosphate). Glu22 and Asp100 have been proposed to participate in the catalytic mechanism and other residues have been proposed to be involved in DNA binding or interactions with the UDP-associated sugar (Morera et al. (1999) "T4 phage beta-glucosyltransferase: substrate binding and proposed catalytic mechanism." J. Mol. Biol. 292(3):717-730, the entire disclosure of which is incorporated herein by reference).

[0035] Accordingly, a variant T4 BGT can be used to add a sugar to a nucleic acid. Variants optionally include an amino acid sequence at least 70% (e.g. at least 75%, at least 80%, at least 82%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) identical to amino acids 1-351, 10-272 or 22-272 of T4 BGT. As assays for glycosylated nucleic acids (e.g. changes in susceptibility to cleavage by a glycosylation-sensitive endonuclease) are readily available, screening for variants retaining enzymatic activity is relatively straightforward.

[0036] Due to the more prominent difference between the 5-gmC and unmodified cytosine, direct observation of its signals in single-molecule sequencing experiments can be achieved using platforms such as PacBio (Pacific Biosciences, Menlo Park, Calif.) or Oxford Nanopore (Oxford, UK).

[0037] Modification-dependent or modification-sensitive endonucleases are described in WO2011/025819 incorporated by reference and also in REBASE® (www.neb.com, New England Biolabs, Ipswich, Mass.) and include for example, MspI, MfeI, Taq, and HpaII endonucleases. Optionally, the endonuclease preferentially binds to a hydroxymethylated cytosine or a glucosyl-oxy-methylated cytosine and cleave the bound nucleic acid at a defined distance from the recognition site. Exemplary endonucleases include those whose amino acid sequences are identical to, or are at least 95% identical to, an enzyme selected from the group consisting of PvuRts1I, PpeHI, EsaSS310P, EsaRBORFBP, PatTI, YkrI, EsaNI, SpeAI, BbiDI, PfrCORF1I80P, PcoORF314P, BmeDI, AbaSI, AbaCI, AbaAI, AbaUMB3ORFAP and Asp6ORFAP, as described in US Patent Application Publication No. 2012/0301881 and/or at least 95% identical to an enzyme referenced in Borgaro et al. (2013) "Characterization of the 5-hydroxymethylcytosine-specific DNA restriction endonucleases," Nucleic Acids Research, doi: 10.1093/nar/gkt102, the entire disclosures of each of which are incorporated herein by reference.

EXAMPLES

Example 1

Expression of mYOX1

[0038] mYOX1 was cloned in E. coli. T7 Express cells (New England Biolabs (NEB), Ipswich, Mass.) transformed with pTXB1-(His)6-mYOX1 which was induced with 50 μM IPTG at OD=0.8. The cells were grown at 16° C. for 12-16 hours and then lysed using a French press. The lysate supernatant was purified on a Ni-based affinity column followed by a heparin-based affinity column. The typical yield of isolated (His)6-mYOX1 was ˜7-8 mg protein/L culture. The pure protein sample was stored in 20 mM TRIS, pH 7.5, 1 mM DTT, 500 mM NaCl, and 50% glycerol at -20° C.

Example 2

Determination of Activity of mYOX1

[0039] (A) Conversion of 5-mC in a double-stranded DNA oligomer with 24 fully-methylated CpG sites ("24× Oligo"), as reflected by the HPLC chromatogram shown in FIG. 4A. The DNA sequence of the top strand, with the methylation sites underlined, is: 5'-ATTACACGCGCGATATCGTTAACGATAATTCGCGCGATTACGATCGATAACGCGTT AATA-3' (SEQ ID NO: 10). For each methylated cytosine in the top strand, the cytosine complementary to the subsequent guanine residue is also methylated, yielding a total of 24 methylated cytosines per double stranded DNA. The assay mix contained in a final volume of 20 μL: 50 mM Bis-TRIS pH 6.0, 50 mM NaCl, 1 mM dithiothreitol (DTT), 2 mM ascorbic acid, 2 mM α-ketoglutarate, 100 μM ferrous sulfate (FeSO₄), 2 μM oligonucleotide (24×), and 4 μM mYOX1.

[0040] The reaction mixture was incubated for 1 hour at 34° C. The protein was digested using proteinase K (NEB) at a final concentration of 1 μg/μL for 1 hour at 50° C. The DNA was recovered by using QIAquick® Nucleotide Removal Kit (QIAGEN, Valencia, Calif.). The recovered DNA was digested by a mixture of 0.5 U nuclease P1 (Sigma-Aldrich, St. Louis, Mo.), 5 U antarctic phosphatase (NEB), 2 U DNAse I (NEB) in 20 μL total volume for 1 hour at 37° C. The digested DNA was then subjected to LC-MS analysis. LC-MS was done on Agilent 1200 series (G1316A UV Detector, 6120 Mass Detector, Agilent, Santa Clara, Calif.) with Waters Atlantis T3 (4.6×150 mm, 3 μm, Waters, Milford, Mass.) column with in-line filter and guard. The results are shown in FIG. 4A, in which the blue profile depicts a reaction mixture without mYOX1 and the red profile depicts a reaction mixture with mYOX1. 5-mC peak is detected in the blue profile, 5-hmC, 5-fC and 5-caC peaks are detected in the red profile. The results of these experiments are summarized in the table below.

TABLE-US-00002 DNA substrate mYOX1 ^caC ^hmC ^mC ^fC 24x oligo - -- -- 100% -- + 89.6% 6.2% 2.0% 2.3% pTXB1-M.Sss1 - -- -- 100% -- + 91.2% 1.8% 1.0% 5.9% IMR90 - -- -- 100% -- + 89.1% 1.7% 0.5% 8.7%

[0041] A variety of buffers and pHs were tested to assess the optimum buffer conditions for 5-mC conversion by mYOX1. The experiment was performed on a double-stranded DNA with one fully-methylated CpG site (5'-CGGCGTTTCCGGGTTCCATAGGCTCCGCCCCGGACTCTGATGACCAGGGCATCAC A-3'; underlined residue is 5-mC, as is the residue complementary to the adjacent guanine residue; SEQ ID NO: 11; "oligo 9"). The results are shown in the table below:

TABLE-US-00003 Buffer ^caC ^hmC ^mC ^fC Citrate pH 5.0 -- -- 100% -- Citrate pH 5.5 -- -- 100% -- MES pH 5.5 10.2% 40.9% 9.2% 39.7% MES pH 5.75 7.7% 42.4% 7.0% 43.0% MES pH 6.0 25.1% 20.8% -- 54.1% Bis-TRIS pH 6.0 38.5% 15.7% 2.1% 43.6% Bis-TRIS pH 6.5 26.1% 19.0% 0.9% 54.0% MOPS pH 6.5 38.8% 13.6% 2.1% 45.4% MOPS pH 6.75 41.7% 10.0% 0.7% 47.5% MOPS pH 7.0 31.7% 18.8% 0.6% 48.9% KH2PO4 pH 7.0 -- -- 100% -- TRIS pH 7.5 5.9% 56.8% 7.1% 30.1% HEPES pH 7.3 20.5% 22.2% 1.0% 56.4% HEPES pH 7.5 18.5% 37.4% 1.2% 42.8% HEPES pH 8.0 -- 16.8% 81.2% 2.0%

[0042] As shown in the table, mYOX1 was active at pH 8.0, oxidizing a portion of the 5-mC to 5-hmC and 5-fC. However, the enzyme was even more active at lower pH. For example, at pH 7.5, approximately 90% of the 5-mC residues were oxidized, with most of the product present as 5-hmC and 5-fC. At pH 7.3, the proportions of 5-mC and 5-hmC decreased, with increasing proportions of 5-fC and 5-caC. The proportions of 5-mC and 5-hmC continued to decrease with decreasing pH through pH 6.0, at which point substantially all of the 5-mC nucleotides were oxidized more than one third to 5-caC. Thus, the enzyme appears to be maximally active at about pH 6. The pH conditions could be used to manipulate distribution of 5-mC oxidation products. The pH-dependence of mYOX1 activity was surprising, as TET enzymes are routinely used at pH 8.

[0043] The activity of mYOX1 was tested on single-stranded DNA (ssDNA) substrates and compared to that of a double-stranded DNA (dsDNA) with the same sequence under the same experimental conditions discussed for 24× oligo. Surprisingly, it was found that mYOX1 oxidizes 5-mC in ssDNA as efficiently as dsDNA. Substrates included double-stranded "oligo 9"; "hemi-oligo 9," a double stranded DNA identical to oligo 9 but lacking methylcytosine on the complementary strand; "ss oligo 9 (top)," a single stranded DNA including only the residues recited in SEQ ID NO: 11; and "ss oligo 9 (bottom)," a single stranded DNA including the residues complementary to the residues recited in SEQ ID NO:11.

TABLE-US-00004 Substrate ^caC ^hmC ^mC ^fC ds oligo 9 80.8% 6.9% 1.7% 10.6% hemi-oligo 9 88.7% 6.3% 1.7% 3.4% ss oligo 9 (top) 92.4% 3.0% 0.4% 1.9% ss oligo 9 94.8 3.0% 0.4% 1.9% (bottom)

[0044] Interestingly, mYOX1 was further shown to exhibit activity on a 1.6 kb RNA substrate ("5-mc RNA") having all its cytosines in 5-mC form:

TABLE-US-00005 (SEQ ID NO: 12) gggtctagaaataattttgtttaactttaagaaggagatatacatatgaaaatcgaagaaggtaaaggtcacca- tcac catcaccacggatccatggaagacgccaaaaacataaagaaaggcccggcgccattctatcctctagaggatgg- aacc gctggagagcaactgcataaggctatgaagagatacgccctggttcctggaacaattgcttttacagatgcaca- tatc gaggtgaacatcacgtacgcggaatacttcgaaatgtccgttcggttggcagaagctatgaaacgatatgggct- gaat acaaatcacagaatcgtcgtatgcagtgaaaactctcttcaattctttatgccggtgttgggcgcgttatttat- cgga gttgcagttgcgcccgcgaacgacatttataatgaacgtgaattgctcaacagtatgaacatttcgcagcctac- cgta gtgtttgtttccaaaaaggggttgcaaaaaattttgaacgtgcaaaaaaaattaccaataatccagaaaattat- tatc atggattctaaaacggattaccagggatttcagtcgatgtacacgttcgtcacatctcatctacctcccggttt- taat gaatacgattttgtaccagagtcctttgatcgtgacaaaacaattgcactgataatgaattcctctggatctac- tggg ttacctaagggtgtggcccttccgcatagaactgcctgcgtcagattctcgcatgccagagatcctatttttgg- caat caaatcattccggatactgcgattttaagtgttgttccattccatcacggttttggaatgtttactacactcgg- atat ttgatatgtggatttcgagtcgtcttaatgtatagatttgaagaagagctgtttttacgatcccttcaggatta- caaa attcaaagtgcgttgctagtaccaaccctattttcattcttcgccaaaagcactctgattgacaaatacgattt- atct aatttacacgaaattgcttctgggggcgcacctctttcgaaagaagtcggggaagcggttgcaaaacgcttcca- tctt ccagggatacgacaaggatatgggctcactgagactacatcagctattctgattacacccgagggggatgataa- accg ggcgcggtcggtaaagttgttccattttttgaagcgaaggttgtggatctggataccgggaaaacgctgggcgt- taat cagagaggcgaattatgtgtcagaggacctatgattatgtccggttatgtaaacaatccggaagcgaccaacgc- cttg attgacaaggatggatggctacattctggagacatagcttactgggacgaagacgaacacttcttcatagttga- ccgc ttgaagtctttaattaaatacaaaggatatcaggtggcccccgctgaattggaatcgatattgttacaacaccc- caac atcttcgacgcgggcgtggcaggtcttcccgacgatgacgccggtgaacttcccgccgccgttgttgttttgga- gcac ggaaagacgatgacggaaaaagagatcgtggattacgtcgccagtcaagtaacaaccgcgaaaaagttgcgcgg- agga gttgtgtttgtggacgaagtaccgaaaggtcttaccggaaaactcgacgcaagaaaaatcagagagatcctcat- aaag gccaagaagggcggaaagtccaaactcgagtaaggttaacctgcaggagg.

The assay conditions were as follows: 50 mM Bis-TRIS pH 6.0, 50 mM NaCl, 1 mM DTT, 2 mM ascorbic acid, 2 mM α-ketoglutarate, 100 μM FeSO₄, 1 μg 5-mC RNA, and 4 μM mYOX1. The reaction mixture was incubated for 1 hour at 34° C. The protein was digested using proteinase K (NEB) at a final concentration of 1 μg/μL for 1 hour at 37° C. The RNA was recovered by using QIAquick® Nucleotide Removal Kit (QIAGEN, Valencia, Calif.). The recovered RNA was digested into nucleosides and analyzed by LC-MS as described in example 2A. The results were as follows:

TABLE-US-00006 DNA substrate mYOX1 r^caC r^hmC r^mC r^fC 5-mC RNA - -- -- 100% -- + -- 40.9% 36.8% 22.3%

(B) Conversion of 5-mC in plasmid and genomic DNA, as depicted in the HPLC chromatogram shown in FIGS. 4B and 4C, respectively. The assay components are as follows: 50 mM Bis-TRIS pH 6.0, 50 mM NaCl, 1 mM DTT, 2 mM ascorbic acid, 2 mM α-ketoglutarate, 100 μM FeSO₄, 2 μg DNA, and 20 μM mYOX1. The reaction mixture was incubated for 1 hour at 34° C. The reaction mixture was then digested with proteinase K for 1 hour at 50° C. The DNA was recovered by using QIAquick® PCR Purification Kit (QIAGEN, Valencia, Calif.). The recovered DNA was digested and analyzed by LC-MS as described in Example 2A. As shown, mYOX1 efficiently oxygenates 5-mC in plasmid and genomic DNA samples. (C) ATP interferes with the chemical processivity of mYOX1 (ability to undergo second and third oxidation steps) as reflected in the table presented below. This is contradictory to what has been described for the TET enzymes where the presence of ATP has been required for the formation of higher amounts of 5-caC. Experimental conditions are as described before for oligos 24× and oligo9.

TABLE-US-00007 1 mM DNA substrate mYOX1 ATP ^caC ^hmC ^mC ^fC oligo9 - - -- -- 100% -- + - 38.7% 15.7% 2.1% 43.6% + + 13.6% 40.9% 2.3% 43.2%

Example 3

mYOX1 can be Used in Conjunction with BGT

[0045] An mYOX1/T4-BGT coupled assay was performed as described in Example 2A for genomic DNA (IMR90), with the following exceptions: 50 mM Hepes pH 7.0 was used instead of Bis-Tris pH 6.0, and 40 μM uridine diphosphoglucose (UDP-Glc) and 50 U T4 BGT were added in the oxidation reaction.

[0046] Alternatively, for bacterial genomic DNA (MG1655), the reaction was carried out exactly as described in Example 2A. Then the reaction mixture was digested with proteinase K for 1 hour at 50° C. The sample was then treated with 100 mM NaBH₄, 40 μM uridine diphosphoglucose (UDP-Glc) and 50 U T4-BGT in 1× NEBuffer 4 (NEB) and incubated for 1 hour at 37° C. The DNA was recovered by using QIAquick® PCR Purification Kit (QIAGEN, Valencia, Calif.). The recovered DNA was digested and analyzed by LC-MS as described in Example 2A, and the results are summarized in the table below.

TABLE-US-00008 Substrate T4-βGT NaBH₄ ^caC ^hmC ^mC β-.sup.ghmC ^fC IMR90 in - 7.4% -- 4.1% 85.9% 2.6% oxidation reaction MG1655 after + 29.3% -- 3.0% 67.7% -- oxidation/ reduction

[0047] The effects of increasing ATP concentration on the activity of mYOX1 when coupled with the activity of T4-BGT in the presence of NaBH₄ and UDP-Glc were tested. ATP concentrations higher than 1 mM exhibit inhibiting effects on the activity of mYOX1 to convert 5-mC to 5-hmC. The reaction was carried out exactly as described in Example 2A for oligo 9 except for the duration of the oxidation reaction (20 minutes instead of 1 hour), and the presence of varying amounts of ATP. The reaction mixture was then digested with proteinase K and glucosylated using T4 BGT as described above for MG1655 genomic DNA. The DNA was recovered by using QIAquick® PCR Purification Kit (QIAGEN, Valencia, Calif.). The recovered DNA was digested and analyzed by LC-MS as described in Example 2A, and the results are summarized in the table below.

TABLE-US-00009 ATP Substrate (mM) ^caC ^hmC ^mC β-.sup.ghmC ^fC Oligo9 0.5 4.8% -- 9.4% 85.8% -- 1 -- -- 13.4% 83.7% -- 2 -- -- 34.4% 65.6% -- 4 -- -- 62.1% 37.9% --

Example 4

Qualitative and Quantitative Assays for Characterization of the mYOX Family of Enzymes

[0048] Immunodot-blot assay: This is a qualitative, but relatively fast assay. Many samples can be tested simultaneously, which can be used for screening purposes, e.g., tracking active fractions during the enzyme purification process. By immobilizing the reacted DNA onto a membrane, it was possible to confirm the identity of the oxidation products of 5-mC, i.e. 5-hmC, 5-fC and 5-caC by probing with specific antibodies (obtainable from Active Motif, Carlsbad, Calif.).

[0049] LC-MS analysis: To quantify mYOX1 oxidation products, LC-MS analysis was performed on a reverse-phase Waters Atlantis T3 C18 column (3 μm, 4.6×150 mm) with an Agilent 1200 LC-MS system equipped with an Agilent G1315D DAD detector and an Agilent 6120 Quadruple MS detector. A binary solvent system with ammonium acetate (10 mM, pH 4.5) and methanol was used. The HPLC method included an isocratic condition with 2% methanol for 10 minutes followed by a slow gradient from 2% to 25% methanol in 30 minutes. The quantification of each nucleoside was based on the peak area by integration of each peak at 278 nm with UV detector. For more accurate quantification, each nucleoside peak can be quantified at its absorption maximum and adjusted by the extinction coefficient constant. The identity of each peak was confirmed by MS.

Example 5

5-hmC sspecific Endonuclease Assay

[0050] We have developed a family of 5-hmC specific endonucleases which digest 5-hmC at the site of ⁵-hmCN₂₂-23G. By cloning the HpaII DNA methylase (C^mCGG) into a vector with only two CCGG sites, the vector will contain two sites of ⁵-mCN₂₂-23G. When the 5-mC in these sites were oxidized to 5-hmC, digestion using the 5-hmC specific endonuclease such as PvuRts1I or AbaSI produced a DNA fragment detectable in an agarose gel. This method detected 5-hmC only.

Example 6

Methods for Sequencing the Methylome and Hydroxymethylome Using the DNA Modification-Dependent Restriction Endonucleases

[0051] Genomic DNA was digested with either MspJI or AbaSI. These enzymes cleaved the DNA at fixed distances from the modified cytosine leaving a sticky end (MspJI: 4-base 5'-overhang; AbaSI: 2-base 3'-overhang). The first biotinylated adaptor (P1b in FIG. 5) was then ligated to the cleaved ends. The ligated DNA was then subjected to random fragmentation to about 300 bp. Avidin beads were used to pull out the fragments with the ligated P1b. After polishing the ends, adaptor P2 was then ligated onto the DNA fragments on the beads. Adaptor-specific PCR was performed and the resultant DNA entered the library preparation pipeline for specific sequencing using the HiSeq® platform (Illumina, San Diego, Calif.). The end-sequencing was done from the P1 end.

[0052] Bioinformatic analysis of the sequencing reads utilized the P1 ends to mark the enzyme's cleavage sites. After mapping the read back to the reference genome, the modified cytosine was determined to be located at a fixed distance away from the cleavage sites and on either side.

Sequence CWU 1

1

121146PRTArtificial SequenceSynthetic construct 1Xaa Xaa Xaa Xaa Xaa His Xaa Asp Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Gly Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Asp Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa His 50 55 60 Xaa Val Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 80 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 85 90 95 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 100 105 110 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 115 120 125 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Arg Xaa Xaa Xaa Xaa Xaa 130 135 140 Phe Ala 145 2321PRTNaegleria gruberi 2Met Thr Thr Phe Lys Gln Gln Thr Ile Lys Glu Lys Glu Thr Lys Arg 1 5 10 15 Lys Tyr Cys Ile Lys Gly Thr Thr Ala Asn Leu Thr Gln Thr His Pro 20 25 30 Asn Gly Pro Val Cys Val Asn Arg Gly Glu Glu Val Ala Asn Thr Thr 35 40 45 Thr Leu Leu Asp Ser Gly Gly Gly Ile Asn Lys Lys Ser Leu Leu Gln 50 55 60 Asn Leu Leu Ser Lys Cys Lys Thr Thr Phe Gln Gln Ser Phe Thr Asn 65 70 75 80 Ala Asn Ile Thr Leu Lys Asp Glu Lys Trp Leu Lys Asn Val Arg Thr 85 90 95 Ala Tyr Phe Val Cys Asp His Asp Gly Ser Val Glu Leu Ala Tyr Leu 100 105 110 Pro Asn Val Leu Pro Lys Glu Leu Val Glu Glu Phe Thr Glu Lys Phe 115 120 125 Glu Ser Ile Gln Thr Gly Arg Lys Lys Asp Thr Gly Tyr Ser Gly Ile 130 135 140 Leu Asp Asn Ser Met Pro Phe Asn Tyr Val Thr Ala Asp Leu Ser Gln 145 150 155 160 Glu Leu Gly Gln Tyr Leu Ser Glu Ile Val Asn Pro Gln Ile Asn Tyr 165 170 175 Tyr Ile Ser Lys Leu Leu Thr Cys Val Ser Ser Arg Thr Ile Asn Tyr 180 185 190 Leu Val Ser Leu Asn Asp Ser Tyr Tyr Ala Leu Asn Asn Cys Leu Tyr 195 200 205 Pro Ser Thr Ala Phe Asn Ser Leu Lys Pro Ser Asn Asp Gly His Arg 210 215 220 Ile Arg Lys Pro His Lys Asp Asn Leu Asp Ile Thr Pro Ser Ser Leu 225 230 235 240 Phe Tyr Phe Gly Asn Phe Gln Asn Thr Glu Gly Tyr Leu Glu Leu Thr 245 250 255 Asp Lys Asn Cys Lys Val Phe Val Gln Pro Gly Asp Val Leu Phe Phe 260 265 270 Lys Gly Asn Glu Tyr Lys His Val Val Ala Asn Ile Thr Ser Gly Trp 275 280 285 Arg Ile Gly Leu Val Tyr Phe Ala His Lys Gly Ser Lys Thr Lys Pro 290 295 300 Tyr Tyr Glu Asp Thr Gln Lys Asn Ser Leu Lys Ile His Lys Glu Thr 305 310 315 320 Lys 3174PRTNaegleria gruberi 3Met Pro Met Asn Tyr Ile Thr Ser Asp Leu Lys Thr Gln Leu Gly Glu 1 5 10 15 Tyr Leu Ile Gly Ile Val Asn Pro Met Leu Asp Glu Thr Ile Thr Ala 20 25 30 Ala Leu Glu Ile Leu Ser Pro Arg Thr Ile Asn Tyr Leu Thr Ser Leu 35 40 45 Pro His Pro Tyr His Ile Leu Asn Asn Cys Ile Tyr Pro Ser Thr Ala 50 55 60 Phe Asn Tyr Leu Glu Pro Gln Ile Glu Lys His Arg Ile Lys Asn Ala 65 70 75 80 His Lys Asp Thr Arg Asp Ala Thr Pro Ser Val Leu Phe Tyr Leu Gly 85 90 95 Asp Tyr Asp Glu Lys Glu Gly Tyr Leu Glu Phe Pro Glu Gln Asn Cys 100 105 110 Lys Val Phe Val Lys Pro Gly Asp Leu Leu Leu Phe Lys Gly Asn Lys 115 120 125 Tyr Lys His Gln Val Ala Pro Ile Thr Ser Gly Thr Arg Leu Gly Leu 130 135 140 Val Tyr Phe Ala His Lys Ala Cys Lys Val Met Asp Phe Tyr Asp Asp 145 150 155 160 Tyr Gln Lys Glu Ser Leu Asn Lys His Lys Gln Gln Asn Gln 165 170 4583PRTNaegleria gruberi 4Met Ser Ile Asn Thr Thr Phe Asn Gln Lys Thr Thr Gln Ser Gly Glu 1 5 10 15 Pro Pro Met Met Met Arg Met Thr Asn Ser Ser Thr Pro Pro Leu Thr 20 25 30 Pro Lys Asn Cys Leu Pro Ile Phe Val Tyr Asn Asp Tyr Gly Lys Leu 35 40 45 Ile Arg Glu Glu Gln Gln Gln Pro Thr Asp Ile Ile Thr Asn Asn Asn 50 55 60 Asn Ser Met Met Arg Ser Met Pro Thr Thr Asn Arg Trp Glu Thr Asn 65 70 75 80 Pro Gln Thr Pro Leu Ser Val Ser Pro Phe Gln Pro Leu Leu Pro Ile 85 90 95 Pro Asn Phe Ser His Ala Phe Ile Val Gly Asn Leu Pro Pro Ser Val 100 105 110 Ser Val Arg Arg Lys Asn Arg Lys Met Ser Glu Lys Pro Lys Asn Asn 115 120 125 Ser Ala Pro Ser Lys Ile Met His Gln Leu Glu Leu Ser Val Leu Asn 130 135 140 Asn Gln Arg Arg Ile Ala Pro Lys Gly Pro Leu Ala Asp Ile Ser Asn 145 150 155 160 Ile Gln Leu Pro Gln Gln Glu Ser Thr Asn Lys Ser Asn Asn Thr Thr 165 170 175 Pro Lys Lys Pro Arg Ile Arg Gln Leu Met Leu Thr Thr Pro Leu Arg 180 185 190 Glu Ser Leu Gln Ser Asn Gln Ser Ala Arg Ser Lys Tyr Ile Asp Glu 195 200 205 Glu Ala Asn Asn Tyr Ser Ile Asn Asp Ser Pro Glu Thr Thr Ile Ile 210 215 220 Lys Thr Ser Asn Thr Lys Asp Ser Glu His Lys Ala Ala Met Ala Thr 225 230 235 240 Asn Leu Gly Leu Ser Thr Asp Asp Phe Glu Cys Lys Pro Phe Glu Thr 245 250 255 Thr Thr Leu Pro Ser Val Ile Asp Lys Asn Tyr Leu Val Val Asp Lys 260 265 270 Glu Gly Cys Thr Gln Leu Ala Leu Leu Pro Asn His Ile Pro Thr Ser 275 280 285 Val Cys Lys Leu Ile Glu Val Lys Cys Arg Lys Val Ser Asn Leu Arg 290 295 300 His Ala Leu Lys Ile Gln Lys Ala Ser Phe Tyr Val Asn Trp Trp Thr 305 310 315 320 Lys Ser Gln Pro Met Gly Tyr Met Cys Lys Asp Asn Glu Ser Glu Ile 325 330 335 Gly Lys Val Val Asn Glu Ile Ala Glu Leu Leu Ser Asp His Cys Arg 340 345 350 Asn Leu Leu Arg Met Cys Asn Glu Arg Val Tyr Lys Lys Ile Ser Glu 355 360 365 Leu Lys Glu Asp Lys Phe Phe Ala Pro Cys Ile Cys Phe Asn Ile Leu 370 375 380 Glu His Asp Leu Glu Ser Arg Ile Thr Lys Phe His His Asp Lys Met 385 390 395 400 Asp Tyr Gly Val Ser Val Leu Phe Tyr Phe Gly Asp Tyr Ser Arg Gly 405 410 415 Asn Leu Asn Val Leu Asp Ala Gly Ser Ser Ser Thr Ile Val Thr Arg 420 425 430 Pro Gly Asp Ala Val Ile Leu Arg Gly Asn Tyr Tyr Lys His Ser Val 435 440 445 Gln Asn Ile Glu Pro Gly Asn Asn Lys Ala Arg Tyr Ser Ile Val Phe 450 455 460 Phe Ala His Ser Thr His Phe Leu Lys Lys Lys Tyr Glu Leu Ser Pro 465 470 475 480 Ala Ala Ala Lys Lys Ala Phe Leu Val Asp Asn Pro Asp Phe Val Ser 485 490 495 Ile Lys Lys Arg Lys Gln Ala Ser Ser Ser Ser Asp Val Ser Val Lys 500 505 510 Lys Ser Lys Lys Ser Thr Glu Asp Asn Val Glu Phe Ile Gln Thr His 515 520 525 Thr Tyr Leu Gly Asn Gly Tyr Lys Ser Gly His Lys Asn Tyr Gln Tyr 530 535 540 Tyr Val Lys Phe Asn Asn Ser Asp Gln Lys Glu Trp Lys Ser Tyr Glu 545 550 555 560 Ser Leu Pro Lys Gln Ala Val Ala Ser Tyr Trp Val Lys Phe Lys Lys 565 570 575 Leu Lys Ser Leu Ser Asn Gln 580 5207PRTNaegleria gruberi 5Met Leu Glu Ala Gln His His Lys Leu Thr Ile Tyr Thr Gly Met Trp 1 5 10 15 Gly His Met Lys Pro Cys Val Phe Ile Ala Ala Asp Asn Cys Asn Lys 20 25 30 Ser Gly Glu Thr Ile Val Glu Asn Leu Leu Phe Lys Leu Gly Lys Ile 35 40 45 Gly Ser Lys Leu Met Glu Ile Leu Ser Pro Phe Thr Met Asn Phe Leu 50 55 60 Ser Ser Leu Asp Pro Glu Ile Phe Leu Asn His Asp Leu Phe Pro Ile 65 70 75 80 Ser Ala Thr Asn Phe Met Ile Pro Gly Asn Lys His Arg Ile Leu Lys 85 90 95 Pro His Lys Asp Asn Gln Asp Val Gly Leu Cys Ile Ile Phe Tyr Phe 100 105 110 Gly Asn Tyr Asn Ala Pro Leu Glu Phe Val Asn Lys Gly Ser Val Phe 115 120 125 Asn Thr Glu Arg Gly Asp Val Leu Leu Met Arg Gly Ser His Phe Arg 130 135 140 His Val Val Lys Pro Val Asp Asn Gly Leu Leu Glu His Val His Asp 145 150 155 160 Pro Met Arg Ile Ser Val Val Leu Phe Ala His Lys Ser Leu Lys Met 165 170 175 Asn Pro Ser Tyr Phe Leu Asn Ala Gly Ser Ala Leu Lys Ala His Asp 180 185 190 Glu Asp Phe Pro Glu Lys Ala Lys Lys Arg Lys Lys Lys Arg Lys 195 200 205 6211PRTNaegleria gruberi 6Met Phe Leu Arg Asn Ile Leu Pro Glu Asn Thr Thr Thr Glu Val Thr 1 5 10 15 Asn Ile Leu Asp Lys Ile Asn Gln Arg Arg Ser Lys Glu Asn Tyr Tyr 20 25 30 Ile Gly Ser Trp Gly Lys Ser Ser Ser Phe Leu Phe Lys Thr Asn Asp 35 40 45 Thr Ile Phe Asn Glu Leu Ser Ser Gln Phe Ile Lys Ile Ile Asn Leu 50 55 60 Leu Lys Asn Tyr Val Leu Glu Ile Leu Lys Phe Gly Asn Asn Lys Met 65 70 75 80 Arg Lys Phe Leu Glu Lys Tyr Asn Ser Ser Asp Phe Leu Ser Ile Tyr 85 90 95 Pro Thr Val Cys Phe Asn Phe Leu Asp Lys Ser Val Asp Glu Asn Arg 100 105 110 Ile Leu His Ile His Pro Asp Lys Glu Asp Thr Gly Thr Ser Leu Ile 115 120 125 Phe Tyr Phe Gly Lys Phe Lys Gly Gly Ala Ile Ser Phe Pro Glu Leu 130 135 140 Asn Phe Lys Leu Met Val Gln Ser Ala Asp Val Leu Leu Phe Asp Gly 145 150 155 160 Lys Asn Asn Leu His Ala Val Glu Ser Leu His Gly Lys Asp Asp Val 165 170 175 Arg Tyr Ser Val Val Phe Phe Ala His Lys Ala Asp Leu Gly Lys Thr 180 185 190 Ser Tyr Pro Met Asn Arg Gly Glu Val Met Lys Gly Ile Lys Asn Lys 195 200 205 Ile Asn Asn 210 7302PRTNaegleria gruberi 7Met Asp Ile Gly Ile Asp Trp Arg Gly Thr His Phe Arg His Lys Asn 1 5 10 15 His Leu Val Lys Glu Glu Val Cys Asp Arg Thr Asn Trp Ile Val Leu 20 25 30 Cys Pro Asn Gly Gln Val Asp Ile Ala Phe Phe Pro Asn Ala Ile Pro 35 40 45 Glu Glu Leu Cys Leu Glu Met Glu Thr Val Val Ala Asn Ser Asp Val 50 55 60 Asp Ile Leu Ser Cys Lys Lys Ala Ile Ile Asp Gly Ser Trp Thr Arg 65 70 75 80 Tyr Gly Asn Gly Ile Tyr Pro Val Lys Thr Ile Thr Thr Asn Gln Ser 85 90 95 Ile Leu Leu His Glu Leu Asn Asp Lys Cys Gly Pro Phe Val Leu Asp 100 105 110 Lys Leu Lys His Ile Asn Lys Asn Met Phe Asn Lys Leu Asp Asn Ile 115 120 125 Asn Glu Asp Ile Lys Asn Tyr Lys Ile Phe Ala Lys Tyr Pro Thr Leu 130 135 140 Ala Leu Asn Val Ser His Asn Glu Asn Tyr Asn Ile Ser Lys Lys Pro 145 150 155 160 Tyr Arg Lys His Thr Asp Gly Asn Asp Ile Gly Leu Gly Val Leu Thr 165 170 175 Tyr Phe Gly Ser Glu Ile Ile Glu Gly Gly Asn Leu Ile Ile His Ile 180 185 190 Glu Asn Leu Lys Val Phe Asn Phe Pro Ile Gln Arg Arg Asp Leu Val 195 200 205 Phe Leu Asn Ser Lys Phe Tyr Ala His Gln Val Thr Lys Val Thr Ser 210 215 220 Gly Ile Arg Phe Gly Leu Val Tyr Phe Ala Gly Glu Ala His Phe Arg 225 230 235 240 Val Arg Asn Asn Asp Asp Phe Leu Pro Ala Leu Pro Phe Asn Ala Asn 245 250 255 Asp Lys Glu Leu Arg Glu Glu Arg Ser Lys Lys Gly Arg Lys Ser Met 260 265 270 Asn Glu Tyr Lys Lys Arg Phe Leu Lys Lys Tyr Leu Arg Glu Lys Lys 275 280 285 Lys Ile Asn Lys Lys Arg Val Lys Cys Lys Asn Lys Leu Lys 290 295 300 8575PRTNaegleria gruberi 8Met Gly Pro Leu His Val Ser Gln His Asp Lys Lys Lys Pro Lys His 1 5 10 15 Arg Arg Arg Lys Lys Gln Phe Leu Lys Ala Gln Ala Leu Thr Arg Val 20 25 30 Cys Trp Glu Asn Glu Lys Ser Ile Asp Glu Ser Gly Lys Thr Arg Val 35 40 45 Tyr Lys Met Ile Lys Glu Trp Glu Phe Leu Lys Gly Asn Asn Ile Gln 50 55 60 Ser Asn Glu Pro Ile Leu Ser Val Tyr Gly Val Asn Asp Thr Ile Pro 65 70 75 80 Lys Glu Ile Ser Ser Asn Thr Ile Ile Val Thr Lys Glu Gly Met Val 85 90 95 Glu Met Ala Leu Leu Lys Ser Val Leu Pro Pro Ser Leu Leu Glu Glu 100 105 110 Cys Thr Gln Leu Cys Arg Glu Met Ser Glu Trp Leu Ala Thr Glu Lys 115 120 125 Asp Ile Asp Lys Gly Ser Phe Phe Ser Gly Trp Trp Thr Met Asn Met 130 135 140 Pro Met Gly Tyr Lys Cys Ala Asp Ser Phe Arg Phe Glu Leu Val Asp 145 150 155 160 Thr Lys Val Lys Gln Ile Gln Ala Leu Leu His Asp Thr Phe Gln His 165 170 175 Ile Leu Glu Leu Ala Asn Pro Lys Leu Phe Ala Lys Leu Ser Lys Leu 180 185 190 Thr Glu Arg Gly Gln Thr Pro Val Val Cys Phe Asn Met Ile Pro Thr 195 200 205 Arg Asn Glu Ser Val Lys Glu Lys Phe Gln Gly Ser Tyr Lys Ser Thr 210 215 220 Asp Lys Val Asn Arg Pro Lys Thr Asn His Arg Asp Arg Asn Asp Met 225 230 235 240 Gly Ile Ser Ala Met Phe Tyr Met Gly Lys Phe Gly Gly Gly Ser Leu 245 250 255 Gln Leu Ile Arg Val Asn Glu His Thr Pro Lys Thr Leu Val His Ile 260 265 270 Gln Ala Gly Asp Val Val Leu Leu Arg Ala Asn Lys Tyr Arg His Ala 275 280 285 Val Ser Pro Thr Arg Pro Gln Ser Phe Pro Leu Ala Asn Ser Ser Gln 290 295 300 Thr Glu Val Asp Asp Val Lys Ile Cys Glu Asn Ser Ser Pro Thr Leu 305 310 315 320 Asn Asn Pro Gln Ala Asp Asp Asn Thr Pro Thr Leu Ile Asn Thr Cys 325

330 335 Pro Lys Gln Glu Pro Thr Asp Gly Asp Asn Pro Val Gln Ser Ser Lys 340 345 350 Glu Pro Ser Asn Asp Tyr Glu Gln Lys Arg Phe Ser Phe Ile Phe Phe 355 360 365 Ala His Arg Ser His Phe Lys His Ser Lys Val Tyr Cys Gly Met Gly 370 375 380 Gln Arg Gln Ala Leu Asn Ala Phe Lys Ala Asp His Pro Tyr Tyr Gln 385 390 395 400 Ser Gln Arg Met Lys Lys Lys Leu Gly Asp Asp Cys Leu Asp Gln Ser 405 410 415 Leu Ile Leu Thr Glu Lys Arg Lys Pro Ile Lys Arg Asn Tyr Ala Leu 420 425 430 Phe Asn Glu Cys Gly Asp Asp Lys Gln Glu Glu Ser Asp Glu Glu Glu 435 440 445 Tyr Gln Gln Tyr Glu Pro Lys Pro Thr Thr Glu Glu Tyr Thr Ile Lys 450 455 460 Val Ile Val Asp His Glu Lys Val Phe Lys Gly Ser Asp Gln Ser Arg 465 470 475 480 Lys Ser Tyr Leu Tyr His Ile Gln Trp Leu Gly Tyr Pro Asp Glu Thr 485 490 495 Trp Glu Pro Tyr Glu His Leu Asp Asp Cys Gln Val Phe Glu Asp Tyr 500 505 510 Leu Lys His His Asn Ile Ser Leu Phe Asp Glu Glu Glu Glu Asp Arg 515 520 525 Lys Val Asp Asp Ser Met Leu Leu Pro Ala Trp Met His Glu Asp Glu 530 535 540 Ser Leu Phe Glu Ala Leu Leu Pro Ile Ile Cys Cys Ser Thr Asp Asn 545 550 555 560 Pro Arg His His Leu Asp Asp Val Pro Pro Phe Asp Phe Asn Tyr 565 570 575 9253PRTNaegleria gruberi 9Met Thr Glu Ile Val Glu Leu Ser Asn Ile Glu Pro Lys Asp Gln Lys 1 5 10 15 Gln Ala Ile Ile Gly Gly Thr Trp Asn Arg Tyr Gly Asn Ser Ile Glu 20 25 30 Ile Val Ala Gly Ile Ser Asp Glu Asn Asn Thr Leu Leu Asp Asn Leu 35 40 45 Thr Asn Cys Cys Glu Ser Phe Val Leu Asp Lys Leu Trp His Leu Asn 50 55 60 Arg Ser Met Tyr Asn Lys Leu Asp Thr Ile Glu Glu Lys Ile Lys Asn 65 70 75 80 Phe Lys Thr Tyr Ala Lys Tyr Pro Ser Leu Ala Leu Asn Leu Leu Cys 85 90 95 Lys Glu Asn Tyr Asn Gly Lys Val Lys Pro Tyr Arg Lys His Ile Asp 100 105 110 Pro Asn Asn Asn Gly Met Asp Val Leu Met Phe Phe Gly Lys Thr Phe 115 120 125 Glu Gly Gly Asn Leu Ile Val Ser Tyr His Tyr Thr Asn Ile Asp Phe 130 135 140 Arg Met Phe Thr Leu Pro Ile Gln Ser Gly Asp Leu Val Phe Leu Asn 145 150 155 160 Ser Arg Ile Tyr His His Lys Val Thr Lys Val Thr Ser Gly Val Arg 165 170 175 Cys Gly Leu Val Phe Phe Ala Gly Leu Asp His Phe Ser Val Arg Lys 180 185 190 Ala Asn Tyr Lys Lys Val Lys Lys Glu Glu Tyr Gln Lys Asn Met Asp 195 200 205 Asp Lys Leu Leu Ala Leu Pro Phe Gln Gln Lys Asp Lys Asp Leu Arg 210 215 220 Ile Glu Arg Thr Lys Thr Gly Arg Lys Glu Ile Lys Gln Phe His Lys 225 230 235 240 Asn Leu Gln Asn Asn Leu Pro Asn Lys Lys Arg Lys Lys 245 250 1060DNAArtificial SequenceSynthetic construct 10attacacgcg cgatatcgtt aacgataatt cgcgcgatta cgatcgataa cgcgttaata 601155DNAArtificial SequenceSynthetic construct 11cggcgtttcc gggttccata ggctccgccc cggactctga tgaccagggc atcac 55121766DNAArtificial SequenceSynthetic construct 12gggtctagaa ataattttgt ttaactttaa gaaggagata tacatatgaa aatcgaagaa 60ggtaaaggtc accatcacca tcaccacgga tccatggaag acgccaaaaa cataaagaaa 120ggcccggcgc cattctatcc tctagaggat ggaaccgctg gagagcaact gcataaggct 180atgaagagat acgccctggt tcctggaaca attgctttta cagatgcaca tatcgaggtg 240aacatcacgt acgcggaata cttcgaaatg tccgttcggt tggcagaagc tatgaaacga 300tatgggctga atacaaatca cagaatcgtc gtatgcagtg aaaactctct tcaattcttt 360atgccggtgt tgggcgcgtt atttatcgga gttgcagttg cgcccgcgaa cgacatttat 420aatgaacgtg aattgctcaa cagtatgaac atttcgcagc ctaccgtagt gtttgtttcc 480aaaaaggggt tgcaaaaaat tttgaacgtg caaaaaaaat taccaataat ccagaaaatt 540attatcatgg attctaaaac ggattaccag ggatttcagt cgatgtacac gttcgtcaca 600tctcatctac ctcccggttt taatgaatac gattttgtac cagagtcctt tgatcgtgac 660aaaacaattg cactgataat gaattcctct ggatctactg ggttacctaa gggtgtggcc 720cttccgcata gaactgcctg cgtcagattc tcgcatgcca gagatcctat ttttggcaat 780caaatcattc cggatactgc gattttaagt gttgttccat tccatcacgg ttttggaatg 840tttactacac tcggatattt gatatgtgga tttcgagtcg tcttaatgta tagatttgaa 900gaagagctgt ttttacgatc ccttcaggat tacaaaattc aaagtgcgtt gctagtacca 960accctatttt cattcttcgc caaaagcact ctgattgaca aatacgattt atctaattta 1020cacgaaattg cttctggggg cgcacctctt tcgaaagaag tcggggaagc ggttgcaaaa 1080cgcttccatc ttccagggat acgacaagga tatgggctca ctgagactac atcagctatt 1140ctgattacac ccgaggggga tgataaaccg ggcgcggtcg gtaaagttgt tccatttttt 1200gaagcgaagg ttgtggatct ggataccggg aaaacgctgg gcgttaatca gagaggcgaa 1260ttatgtgtca gaggacctat gattatgtcc ggttatgtaa acaatccgga agcgaccaac 1320gccttgattg acaaggatgg atggctacat tctggagaca tagcttactg ggacgaagac 1380gaacacttct tcatagttga ccgcttgaag tctttaatta aatacaaagg atatcaggtg 1440gcccccgctg aattggaatc gatattgtta caacacccca acatcttcga cgcgggcgtg 1500gcaggtcttc ccgacgatga cgccggtgaa cttcccgccg ccgttgttgt tttggagcac 1560ggaaagacga tgacggaaaa agagatcgtg gattacgtcg ccagtcaagt aacaaccgcg 1620aaaaagttgc gcggaggagt tgtgtttgtg gacgaagtac cgaaaggtct taccggaaaa 1680ctcgacgcaa gaaaaatcag agagatcctc ataaaggcca agaagggcgg aaagtccaaa 1740ctcgagtaag gttaacctgc aggagg 1766

Claims

1.-48. (canceled)

49. A fusion protein, comprising: a binding domain fused to a recombinant 5-methylpyrimidine oxygenase (mYOX) having a size less than 600 amino acids and having a catalytic domain having at least 90% sequence identity with SEQ ID NO:1.

50. The fusion protein according to claim 49, wherein the binding domain is selected from the group consisting of: a His-tag, a maltose-binding protein, a chitin binding domain, and a DNA binding domain.

51. The fusion protein according to claim 49 having the DNA binding domain comprising a zinc finger or transcription activator-like (TAL) effector domain.

52. A composition comprising: a buffer and a purified 5-methylpyrimidine oxygenase having a size less than 600 amino acids and having a catalytic domain having at least 90% identity with SEQ ID NO:1.

53. A composition according to claim 52, wherein the buffer does not contain ATP.

54. A composition according to claim 52, wherein the buffer contains ATP.

55. A composition according to claim 52, wherein the buffer is at a pH from about 6 to about 8.

56. A composition according to claim 55, wherein the buffer is at a pH from about 6 to about 7.5.

57. A composition according to claim 52, wherein the buffer contains Fe(II) and α-ketoglutarate.

58. A composition according to claim 52, further comprising a nucleic acid.

59. A kit comprising a composition according to claim 52 and a separate reaction buffer.

60. A kit according to claim 59, wherein the reaction buffer is at a pH from about 6 to about 7.5.

61. A kit according to claim 59, wherein the reaction buffer contains ATP.

62. A kit according to claim 59, wherein the reaction buffer does not contain ATP.

63. A kit according to claim 59, further comprising a nucleic acid.

64. A kit according to claim 59, further comprising a reducing agent.

65. A kit according to claim 59, further comprising a β-glycosyltransferase (BGT) and UDP-glucosamine.

66. A kit according to claim 59, further comprising a β-glycosyltransferase (BGT) and UDP-glucose.

67. A kit according to claim 59, further comprising a DNA glycosylase.

68. A kit according to claim 59, further comprising an endonuclease.

69. A method for differentiating a 5-methylcytosine (5-mC) from 5-hydroxymethylcytosine (5-hmC) in a genome or genome fragment, comprising: (a) reacting the isolated genome or genome fragment containing 5-mC and 5-hmC with UDP-glucose or UDP-glucosamine; a glycosyltransferase for transferring glucose or glucosamine to the 5hmC; and a composition according to claim 52; (b) cleaving the glucosylated template with a modification-dependent endonuclease that recognizes at least one of the modified nucleotides; and (c) differentiating the 5-mC from the 5-hmC by an altered cleavage pattern.

70. A method according to claim 69, wherein the modification-dependent endonuclease is AbaSI.