Enzyme Nomenclature

EC 2.1.1 (continued)

Methyltransferases

Continued from:
EC 2.1.1.1 to EC 2.1.1.50
EC 2.1.1.51 to EC 2.1.1.100
See separate file for EC 2.1.1.151 to EC 2.1.1.200, EC 2.1.1.201 to EC 2.1.1.250, EC 2.1.1.251 to EC 2.1.1.300 and EC 2.1.1.301 to EC 2.1.1.353.

Contents

EC 2.1.1.101 macrocin O-methyltransferase
EC 2.1.1.102 demethylmacrocin O-methyltransferase
EC 2.1.1.103 phosphoethanolamine N-methyltransferase
EC 2.1.1.104 caffeoyl-CoA O-methyltransferase
EC 2.1.1.105 N-benzoyl-4-hydroxyanthranilate 4-O-methyltransferase
EC 2.1.1.106 tryptophan 2-C-methyltransferase
EC 2.1.1.107 uroporphyrinogen-III C-methyltransferase
EC 2.1.1.108 6-hydroxymellein O-methyltransferase
EC 2.1.1.109 demethylsterigmatocystin 6-O-methyltransferase
EC 2.1.1.110 sterigmatocystin 8-O-methyltransferase
EC 2.1.1.111 anthranilate N-methyltransferase
EC 2.1.1.112 glucuronoxylan 4-O-methyltransferase
EC 2.1.1.113 site-specific DNA-methyltransferase (cytosine-N4-specific)
EC 2.1.1.114 polyprenyldihydroxybenzoate methyltransferase
EC 2.1.1.115 (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase
EC 2.1.1.116 3'-hydroxy-N-methyl-(S)-coclaurine 4'-O-methyltransferase
EC 2.1.1.117 (S)-scoulerine 9-O-methyltransferase
EC 2.1.1.118 columbamine O-methyltransferase
EC 2.1.1.119 10-hydroxydihydrosanguinarine 10-O-methyltransferase
EC 2.1.1.120 12-hydroxydihydrochelirubine 12-O-methyltransferase
EC 2.1.1.121 6-O-methylnorlaudanosoline 5'-O-methyltransferase
EC 2.1.1.122 (S)-tetrahydroprotoberberine N-methyltransferase
EC 2.1.1.123 [cytochrome c]-methionine S-methyltransferase
EC 2.1.1.124 deleted covered by EC 2.1.1.319, EC 2.1.1.320, EC 2.1.1.321 and EC 2.1.1.322
EC 2.1.1.125 deleted covered by EC 2.1.1.319, EC 2.1.1.320, EC 2.1.1.321 and EC 2.1.1.322
EC 2.1.1.126 deleted covered by EC 2.1.1.319, EC 2.1.1.320, EC 2.1.1.321 and EC 2.1.1.322
EC 2.1.1.127 [ribulose-bisphosphate carboxylase]-lysine N-methyltransferase
EC 2.1.1.128 (RS)-norcoclaurine 6-O-methyltransferase
EC 2.1.1.129 inositol 4-methyltransferase
EC 2.1.1.130 precorrin-2 C20-methyltransferase
EC 2.1.1.131 precorrin-3B C17-methyltransferase
EC 2.1.1.132 precorrin-6B C5,15-methyltransferase (decarboxylating)
EC 2.1.1.133 precorrin-4 C11-methyltransferase
EC 2.1.1.134 now with EC 2.1.1.129
EC 2.1.1.135 now EC 1.16.1.8
EC 2.1.1.136 chlorophenol O-methyltransferase
EC 2.1.1.137 arsenite methyltransferase
EC 2.1.1.138 deleted
EC 2.1.1.139 3'-demethylstaurosporine O-methyltransferase
EC 2.1.1.140 (S)-coclaurine-N-methyltransferase
EC 2.1.1.146 (iso)eugenol O-methyltransferase
EC 2.1.1.147 corydaline synthase
EC 2.1.1.148 thymidylate synthase (FAD)
EC 2.1.1.149 myricetin O-methyltransferase
EC 2.1.1.141 jasmonate O-methyltransferase
EC 2.1.1.142 cycloartenol 24-C-methyltransferase
EC 2.1.1.143 24-methylenesterol C-methyltransferase
EC 2.1.1.144 trans-aconitate 2-methyltransferase
EC 2.1.1.145 trans-aconitate 3-methyltransferase
EC 2.1.1.146 (iso)eugenol O-methyltransferase
EC 2.1.1.147 corydaline synthase
EC 2.1.1.148 thymidylate synthase (FAD)
EC 2.1.1.149 deleted, now covered by EC 2.1.1.267
EC 2.1.1.150 isoflavone 7-O-methyltransferase

See the following files for:
EC 2.1.1.151 to EC 2.1.1.200
EC 2.1.1.201 to EC 2.1.1.250
EC 2.1.1.251 to EC 2.1.1.300
EC 2.1.1.301 to EC 2.1.1.353

Entries

EC 2.1.1.101

Accepted name: macrocin O-methyltransferase

Reaction: S-adenosyl-L-methionine + macrocin = S-adenosyl-L-homocysteine + tylosin

For diagram of reaction click here.

Other name(s): macrocin methyltransferase; S-adenosyl-L-methionine-macrocin O-methyltransferase; MOMT (ambiguous); tylF (gene name)

Systematic name: S-adenosyl-L-methionine:macrocin 3"'-O-methyltransferase

Comments: Requires Mg2+, Mn2+ or Co2+. The 3-hydroxy group of the 2-O-methyl-6-deoxy-D-allose moiety in the macrolide antibiotic macrosin acts as methyl acceptor, generating tylosin, another macrolide antibiotic. Isolated from the bacterium Streptomyces fradiae. Not identical with EC 2.1.1.102, demethylmacrocin O-methyltransferase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 79468-52-3

References:

1. Bauer, N.J., Kreuzman, A.J., Dotzlaf, J.E. and Yeh, W.-K. Purification, characterization, and kinetic mechanism of S-adenosyl-L-methionine:macrocin O-methyltransferase from Streptomyces fradiae. J. Biol. Chem. 263 (1988) 15619-15625. [PMID: 3170601]

2. Kreuzman, A.J., Turner, J.R. and Yeh, W.-K. Two distinctive O-methyltransferases catalyzing penultimate and terminal reactions of macrolide antibiotic (tylosin) biosynthesis. Substrate specificity, enzyme inhibition, and kinetic mechanism. J. Biol. Chem. 263 (1988) 15626-15633. [PMID: 3170602]

[EC 2.1.1.101 created 1992]

EC 2.1.1.102

Accepted name: demethylmacrocin O-methyltransferase

Reaction: S-adenosyl-L-methionine + demethylmacrocin = S-adenosyl-L-homocysteine + macrocin

For diagram of reaction click here.

Other name(s): demethylmacrocin methyltransferase; DMOMT

Systematic name: S-adenosyl-L-methionine:demethylmacrocin 2'''-O-methyltransferase

Comments: Requires Mg2+. The enzyme, isolated from the bacterium Streptomyces fradiae, is involved in the biosynthesis of the macrolide antibiotic tylosin. The 2-hydroxy group of a 6-deoxy-D-allose moiety in demethylmacrocin acts as the methyl acceptor. Also acts on demethyllactenocin, giving lactenocin. Not identical with EC 2.1.1.101 macrocin O-methyltransferase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 120313-64-6

References:

1. Kreuzman, A.J., Turner, J.R. and Yeh, W.-K. Two distinctive O-methyltransferases catalyzing penultimate and terminal reactions of macrolide antibiotic (tylosin) biosynthesis. Substrate specificity, enzyme inhibition, and kinetic mechanism. J. Biol. Chem. 263 (1988) 15626-15633. [PMID: 3170602]

[EC 2.1.1.102 created 1992]

EC 2.1.1.103

Accepted name: phosphoethanolamine N-methyltransferase

Reaction: S-adenosyl-L-methionine + ethanolamine phosphate = S-adenosyl-L-homocysteine + N-methylethanolamine phosphate

Other name(s): phosphoethanolamine methyltransferase

Systematic name: S-adenosyl-L-methionine:ethanolamine-phosphate N-methyltransferase

Comments: The enzyme may catalyse the transfer of two further methyl groups to the product.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 171040-79-2

References:

1. Datko, A.H. and Mudd, S.H. Enzymes of phosphatidylcholine synthesis in Lemna, soybean, and carrot. Plant Physiol. 88 (1988) 1338-1348.

[EC 2.1.1.103 created 1992]

EC 2.1.1.104

Accepted name: caffeoyl-CoA O-methyltransferase

Reaction: S-adenosyl-L-methionine + caffeoyl-CoA = S-adenosyl-L-homocysteine + feruloyl-CoA

Other name(s): caffeoyl coenzyme A methyltransferase; caffeoyl-CoA 3-O-methyltransferase; trans-caffeoyl-CoA 3-O-methyltransferase

Systematic name: S-adenosyl-L-methionine:caffeoyl-CoA 3-O-methyltransferase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 120433-42-3

References:

1. Kühnl, T., Koch, U., Heller, W. and Wellmann, E. Elicitor induced S-adenosyl-L-methionine - caffeoyl-CoA 3-O-methyltransferase from carrot cell-suspension cultures. Plant Sci. 60 (1989) 21-25.

[EC 2.1.1.104 created 1992]

EC 2.1.1.105

Accepted name: N-benzoyl-4-hydroxyanthranilate 4-O-methyltransferase

Reaction: S-adenosyl-L-methionine + N-benzoyl-4-hydroxyanthranilate = S-adenosyl-L-homocysteine + N-benzoyl-4-methoxyanthranilate

Other name(s): N-benzoyl-4-hydroxyanthranilate 4-methyltransferase; benzoyl-CoA:anthranilate N-benzoyltransferase

Systematic name: S-adenosyl-L-methionine:N-benzoyl-4-O-hydroxyanthranilate 4-O-methyltransferase

Comments: Involved in the biosynthesis of phytoalexins.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 125498-68-2

References:

1. Reinhard, K. and Matern, U. The biosynthesis of phytoalexins in Dianthus caryophyllus L. cell cultures: induction of benzoyl-CoA:anthranilate N-benzoyltransferase activity. Arch. Biochem. Biophys. 275 (1989) 295-301. [PMID: 2817901]

[EC 2.1.1.105 created 1992]

EC 2.1.1.106

Accepted name: tryptophan 2-C-methyltransferase

Reaction: S-adenosyl-L-methionine + L-tryptophan = S-adenosyl-L-homocysteine + L-2-methyltryptophan

Other name(s): tsrM (gene name); tryptophan 2-methyltransferase; S-adenosylmethionine:tryptophan 2-methyltransferase

Systematic name: S-adenosyl-L-methionine:L-tryptophan 2-C-methyltransferase

Comments: The enzyme, characterized from the bacterium Streptomyces laurentii, is involved in thiostrepton biosynthesis. It is a radical SAM enzyme that contains a [4Fe-4S] center and a cobalamin cofactor. The enzyme first transfers the methyl group from SAM to the bound cobalamin, followed by transfer from methylcobalamin to L-tryptophan, resulting in retention of the original methyl group configuration. The second transfer is likely to involve a CH3 radical species formed from methylcobalamin by the concerted action of a partially ligated radical SAM [4Fe-4S]2+/1+ center.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 126626-83-3

References:

1. Frenzel, T., Zhou, P. and Floss, H.G. Formation of 2-methyltryptophan in the biosynthesis of thiostrepton: isolation of S-adenosylmethionine:tryptophan 2-methyltransferase. Arch. Biochem. Biophys. 278 (1990) 35-40. [PMID: 2321967]

2. Pierre, S., Guillot, A., Benjdia, A., Sandstrom, C., Langella, P. and Berteau, O. Thiostrepton tryptophan methyltransferase expands the chemistry of radical SAM enzymes. Nat. Chem. Biol. 8 (2012) 957-959. [PMID: 23064318]

3. Blaszczyk, A.J., Silakov, A., Zhang, B., Maiocco, S.J., Lanz, N.D., Kelly, W.L., Elliott, S.J., Krebs, C. and Booker, S.J. Spectroscopic and electrochemical characterization of the iron-sulfur and cobalamin cofactors of TsrM, an unusual radical S-adenosylmethionine methylase. J. Am. Chem. Soc. 138 (2016) 3416-3426. [PMID: 26841310]

4. Blaszczyk, A.J., Wang, B., Silakov, A., Ho, J.V. and Booker, S.J. Efficient methylation of C2 in L-tryptophan by the cobalamin-dependent radical S-adenosylmethionine methylase TsrM requires an unmodified N1 amine. J. Biol. Chem. 292 (2017) 15456-15467. [PMID: 28747433]

[EC 2.1.1.106 created 1992]

EC 2.1.1.107

Accepted name: uroporphyrinogen-III C-methyltransferase

Reaction: 2 S-adenosyl-L-methionine + uroporphyrinogen III = 2 S-adenosyl-L-homocysteine + precorrin-2 (overall reaction)
(1a) S-adenosyl-L-methionine + uroporphyrinogen III = S-adenosyl-L-homocysteine + precorrin-1

(ab) S-adenosyl-L-methionine + precorrin-1 = S-adenosyl-L-homocysteine + precorrin-2

For diagram click here.

Glossary: uroprphyrinogen-III = 5,10,15,20,22,24-hexahydrouroporphyrin-III

Other name(s): uroporphyrinogen methyltransferase; uroporphyrinogen-III methyltransferase; adenosylmethionine-uroporphyrinogen III methyltransferase; S-adenosyl-L-methionine-dependent uroporphyrinogen III methylase; uroporphyrinogen-III methylase; SirA; CysG; CobA [ambiguous — see EC 2.5.1.17]; SUMT; uroporphyrin-III C-methyltransferase (incorrect); S-adenosyl-L-methionine:uroporphyrin-III C-methyltransferase (incorrect)

Systematic name: S-adenosyl-L-methionine:uroporphyrinogen-III C-methyltransferase

Comments: This enzyme catalyses two sequential methylation reactions, the first forming precorrin-1 and the second leading to the formation of precorrin-2. It is the first of three steps leading to the formation of siroheme from uroporphyrinogen III. The second step involves an NAD+-dependent dehydrogenation to form sirohydrochlorin from precorrin-2 (EC 1.3.1.76, precorrin-2 dehydrogenase) and the third step involves the chelation of Fe2+ to sirohydrochlorin to form siroheme (EC 4.99.1.4, sirohydrochlorin ferrochelatase). In Saccharomyces cerevisiae, the last two steps are carried out by a single bifunctional enzyme, Met8p. In some bacteria, steps 1-3 are catalysed by a single multifunctional protein called CysG, whereas in Bacillus megaterium, three separate enzymes carry out each of the steps, with SirA being responsible for the above reaction. Also involved in the biosynthesis of cobalamin.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 125752-76-3

References:

1. Warren, M.J., Gonzalez, M.D., Williams, H.J., Stolowich, N.J. and Scott, A.I. Uroporphyrinogen-III methylase catalyzes the enzymatic-synthesis of sirohydrochlorin-II and sirohydrochlorin-IV by a clockwise mechanism. J. Am. Chem. Soc. 112 (1990) 5343-5345.

2. Warren, M.J., Roessner, C.A., Santander, P.J. and Scott, A.I. The Escherichia coli cysG gene encodes S-adenosylmethionine-dependent uroporphyrinogen III methylase. Biochem. J. 265 (1990) 725-729. [PMID: 2407234]

3. Schubert, H.L., Raux, E., Brindley, A.A., Leech, H.K., Wilson, K.S., Hill, C.P. and Warren, M.J. The structure of Saccharomyces cerevisiae Met8p, a bifunctional dehydrogenase and ferrochelatase. EMBO J. 21 (2002) 2068-2075. [PMID: 11980703]

[EC 2.1.1.107 created 1992, modified 2004]

EC 2.1.1.108

Accepted name: 6-hydroxymellein O-methyltransferase

Reaction: S-adenosyl-L-methionine + 6-hydroxymellein = S-adenosyl-L-homocysteine + 6-methoxymellein

Other name(s): 6-hydroxymellein methyltransferase

Systematic name: S-adenosyl-L-methionine:6-hydroxymellein 6-O-methyltransferase

Comments: 3,4-Dehydro-6-hydroxymellein can also act as acceptor. 6-Methoxymellein is a phytoalexin produced by carrot tissue.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 124149-02-6

References:

1. Kurosaki, F. and Nishi, A. A methyltransferase for synthesis of the phytoalexin 6-methoxymellein in carrot cells. FEBS Lett. 227 (1988) 183-186.

[EC 2.1.1.108 created 1992]

EC 2.1.1.109

Accepted name: demethylsterigmatocystin 6-O-methyltransferase

Reaction: S-adenosyl-L-methionine + 6-demethylsterigmatocystin = S-adenosyl-L-homocysteine + sterigmatocystin

For diagram click here.

Other name(s): demethylsterigmatocystin methyltransferase; O-methyltransferase I

Systematic name: S-adenosyl-L-methionine:6-demethylsterigmatocystin 6-O-methyltransferase

Comments: Dihydrodemethylsterigmatocystin can also act as acceptor. Involved in the biosynthesis of aflatoxins in fungi.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 123516-47-2

References:

1. Yabe, K., Ando, Y., Hashimoto, J. and Hamasaki, T. 2 distinct O-methyltransferases in aflatoxin biosynthesis. Appl. Environ. Microbiol. 55 (1989) 2172-2177.

[EC 2.1.1.109 created 1992]

EC 2.1.1.110

Accepted name: sterigmatocystin 8-O-methyltransferase

Reaction: (1) S-adenosyl-L-methionine + sterigmatocystin = S-adenosyl-L-homocysteine + 8-O-methylsterigmatocystin
(2) S-adenosyl-L-methionine + dihydrosterigmatocystin = S-adenosyl-L-homocysteine + 8-O-methyldihydrosterigmatocystin

For diagram of reaction click here.

Glossary: sterigmatocystin = 3a,12c-dihydro-8-hydroxy-6-methoxyfuro[3',2':4,5]furo[2,3-c]xanthen-7-one
dihydrosterigmatocystin = 1,2,3a,12c-tetrahydro-8-hydroxy-6-methoxyfuro[3',2':4,5]furo[2,3-c]xanthen-7-one
8-O-methylsterigmatocystin = 6,8-dimethoxy-3a,12c-dihydrofuro[3',2':4,5]furo[2,3-c]xanthen-7-one
8-O-methyldihydrosterigmatocystin = 6,8-dimethoxy-1,2,3a,12c-tetrahydrofuro[3',2':4,5]furo[2,3-c]xanthen-7-one

Other name(s): sterigmatocystin methyltransferase; O-methyltransferase II; sterigmatocystin 7-O-methyltransferase (incorrect); S-adenosyl-L-methionine:sterigmatocystin 7-O-methyltransferase (incorrect); OmtA

Systematic name: S-adenosyl-L-methionine:sterigmatocystin 8-O-methyltransferase

Comments: Dihydrosterigmatocystin can also act as acceptor. Involved in the biosynthesis of aflatoxins in fungi.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 116958-29-3

References:

1. Bhatnagar, D., McCormick, S.P., Lee, L.S. and Hill, R.A. Identification of O-methylsterigmatocystin as an aflatoxin B1 and G1 precursor in Aspergillus parasiticus. Appl. Environ. Microbiol. 53 (1987) 1028-1033. [PMID: 3111363]

2. Yabe, K., Ando, Y., Hashimoto, J. and Hamasaki, T. 2 distinct O-methyltransferases in aflatoxin biosynthesis. Appl. Environ. Microbiol. 55 (1989) 2172-2177. [PMID: 2802602]

3. Yu, J., Cary, J.W., Bhatnagar, D., Cleveland, T.E., Keller, N.P. and Chu, F.S. Cloning and characterization of a cDNA from Aspergillus parasiticus encoding an O-methyltransferase involved in aflatoxin biosynthesis. Appl. Environ. Microbiol. 59 (1993) 3564-3571. [PMID: 8285664]

4. Lee, L.W., Chiou, C.H. and Linz, J.E. Function of native OmtA in vivo and expression and distribution of this protein in colonies of Aspergillus parasiticus. Appl. Environ. Microbiol. 68 (2002) 5718-5727. [PMID: 12406770]

[EC 2.1.1.110 created 1992, modified 2005, modified 2013]

EC 2.1.1.111

Accepted name: anthranilate N-methyltransferase

Reaction: S-adenosyl-L-methionine + anthranilate = S-adenosyl-L-homocysteine + N-methylanthranilate

For diagram click here.

Other name(s): anthranilic acid N-methyltransferase

Systematic name: S-adenosyl-L-methionine:anthranilate N-methyltransferase

Comments: Involved in the biosynthesis of acridine alkaloids in plant tissues.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 123779-15-7

References:

1. Eilert, U. and Wolters, B. Elicitor induction of S-adenosyl-L-methionine-anthranilic acid N-methyltransferase activity in cell-suspension and organ-cultures of Ruta graveolens L. Plant Cell, Tissue Organ Cult. 18 (1989) 1-18.

[EC 2.1.1.111 created 1992]

EC 2.1.1.112

Accepted name: glucuronoxylan 4-O-methyltransferase

Reaction: S-adenosyl-L-methionine + glucuronoxylan D-glucuronate = S-adenosyl-L-homocysteine + glucuronoxylan 4-O-methyl-D-glucuronate

Systematic name: S-adenosyl-L-methionine:glucuronoxylan-D-glucuronate 4-O-methyltransferase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 123644-79-1

References:

1. Baydoun, E.A.-H., Usta, J.A.-R., Waldron, K.W. and Brett, C.T. A methyltransferase involved in the biosynthesis of 4-O-methylglucuronoxylan in etiolated pea epicotyls. J. Plant Physiol. 135 (1989) 81-85.

[EC 2.1.1.112 created 1992]

EC 2.1.1.113

Accepted name: site-specific DNA-methyltransferase (cytosine-N4-specific)

Reaction: S-adenosyl-L-methionine + DNA cytosine = S-adenosyl-L-homocysteine + DNA N4-methylcytosine

Other name(s): modification methylase; restriction-modification system; DNA[cytosine-N4]methyltransferase; m4C-forming MTase

Systematic name: S-adenosyl-L-methionine:DNA-cytosine N4-methyltransferase

Comments: This is a large group of enzymes, most of which, with enzymes of similar site specificity listed as EC 3.1.21.3 (type 1 site-specific deoxyribonuclease), EC 3.1.21.4 (type II site-specific deoxyribonuclease) or EC 3.1.21.5 (type III site-specific deoxyribonuclease), form so-called 'restriction-modification systems'. A complete listing of all of these enzymes has been produced by R.J. Roberts and is available on-line at http://rebase.neb.com/rebase/rebase.html.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 169592-50-1

References:

1. Kessler, C. and Manta, V. Specificity of restriction endonucleases and DNA modification methyltransferases. A review (Edition 3). Gene 92 (1990) 1-248. [PMID: 2172084]

2. Klimasauskas, S., Timinskas, A., Menkevicius, S., Butkiene, D., Butkus, V. and Janulaitis, A. Sequence motifs characteristic of DNA[cytosine-N4]methyltransferases: similarity to adenine and cytosine-C5 DNA-methylases. Nucleic Acids Res. 17 (1989) 9823-9832. [PMID: 2690010]

3. Roberts, R.J. Restriction enzymes and their isoschizomers. Nucleic Acids Res. 18 (1990) 2331-2365. [PMID: 2159140]

4. Yuan, R. Structure and mechanism of multifunctional restriction endonucleases. Annu. Rev. Biochem. 50 (1981) 285-319. [PMID: 6267988]

[EC 2.1.1.113 created 1992]

EC 2.1.1.114

Accepted name: polyprenyldihydroxybenzoate methyltransferase

Reaction: S-adenosyl-L-methionine + 3,4-dihydroxy-5-all-trans-polyprenylbenzoate = S-adenosyl-L-homocysteine + 3-methoxy-4-hydroxy-5-all-trans-polyprenylbenzoate

For diagram of reaction click here.

Other name(s): 3,4-dihydroxy-5-hexaprenylbenzoate methyltransferase; dihydroxyhexaprenylbenzoate methyltransferase; COQ3 (gene name); Coq3 O-methyltransferase; DHHB O-methyltransferase

Systematic name: S-adenosyl-L-methionine:3,4-dihydroxy-5-all-trans-polyprenylbenzoate 3-O-methyltransferase

Comments: This enzyme is involved in ubiquinone biosynthesis. Ubiquinones from different organisms have a different number of prenyl units (for example, ubiquinone-6 in Saccharomyces, ubiquinone-9 in rat and ubiquinone-10 in human), and thus the natural substrate for the enzymes from different organisms has a different number of prenyl units. However, the enzyme usually shows a low degree of specificity regarding the number of prenyl units. For example, the human COQ3 enzyme can restore biosynthesis of ubiquinone-6 in coq3 deletion mutants of yeast [3]. The enzymes from yeast and rat also catalyse the methylation of 3-demethylubiquinol-6 and 3-demethylubiquinol-9, respectively [2] (this activity is classified as EC 2.1.1.64, 3-demethylubiquinol 3-O-methyltransferase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 139569-31-6

References:

1. Clarke, C.F., Williams, W., Teruya, J.H. Ubiquinone biosynthesis in Saccharomyces cerevisiae. Isolation and sequence of COQ3, the 3,4-dihydroxy-5-hexaprenylbenzoate methyltransferase gene. J. Biol. Chem. 266 (1991) 16636-16641. [PMID: 1885593]

2. Poon, W.W., Barkovich, R.J., Hsu, A.Y., Frankel, A., Lee, P.T., Shepherd, J.N., Myles, D.C. and Clarke, C.F. Yeast and rat Coq3 and Escherichia coli UbiG polypeptides catalyze both O-methyltransferase steps in coenzyme Q biosynthesis. J. Biol. Chem. 274 (1999) 21665-21672. [PMID: 10419476]

3. Jonassen, T. and Clarke, C.F. Isolation and functional expression of human COQ3, a gene encoding a methyltransferase required for ubiquinone biosynthesis. J. Biol. Chem. 275 (2000) 12381-12387. [PMID: 10777520]

4. Xing, L., Zhu, Y., Fang, P., Wang, J., Zeng, F., Li, X., Teng, M. and Li, X. Crystallization and preliminary crystallographic studies of UbiG, an O-methyltransferase from Escherichia coli. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 67 (2011) 727-729. [PMID: 21636923]

[EC 2.1.1.114 created 1999, modified 2011]

EC 2.1.1.115

Accepted name: (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase

Reaction: S-adenosyl-L-methionine + (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline = S-adenosyl-L-homocysteine + N-methyl-(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline

Other name(s): norreticuline N-methyltransferase

Systematic name: S-adenosyl-L-methionine:(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase

Comments: broad substrate specificity for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines; including coclaurine, norcoclaurine, isococlaurine, norarmepavine, norreticuline and tetrahydropapaverine. Both R- and S-enantiomers are methylated. The enzyme participates in the pathway leading to benzylisoquinoline alkaloid synthesis in plants. The physiological substrate is likely to be coclaurine. The enzyme was earlier termed norreticuline N-methyltransferase. However, norreticuline has not been found to occur in nature and that name does not reflect the broad specificity of the enzyme for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 132084-82-3

References:

1. Frenzel, T., Zenk, M.H. Purification and characterization of three isoforms of S-adenosyl-L-methionine: (R,S)-tetrahydrobenzyl-isoquinoline N-methyltransferase from Berberis koetineana cell cultures. Phytochemistry 29 (1990) 3491-3497.

[EC 2.1.1.115 created 1999]

EC 2.1.1.116

Accepted name: cyanidin 3-O-rutinoside 5-O-glucosyltransferase

Reaction: UDP-α-D-glucose + cyanidin-3-O-rutinoside = UDP + cyanidin 3-O-rutinoside 5-O-β-D-glucoside

For diagram of reaction click here.

Glossary: cyanidin 3-O-rutinoside = cyanidin-3-O-α-L-rhamnosyl-(1→6)-β-D-glucoside
cyanidin = 3,3',4',5,7-pentahydroxyflavylium

Other name(s): uridine diphosphoglucose-cyanidin 3-rhamnosylglucoside 5-O-glucosyltransferase; cyanidin-3-rhamnosylglucoside 5-O-glucosyltransferase; UDP-glucose:cyanidin-3-O-D-rhamnosyl-1,6-D-glucoside 5-O-D-glucosyltransferase

Systematic name: UDP-α-D-glucose:cyanidin-3-O-α-L-rhamnosyl-(1→6)-β-D-glucoside 5-O-β-D-glucosyltransferase

Comments: Isolated from the plants Silene dioica (red campion) [1], Iris ensata (Japanese iris) [2] and Iris hollandica (Dutch iris) [3]. Also acts on the 3-O-rutinosides of pelargonidin, delphinidin and malvidin, but not the corresponding glucosides or 6-acylglucosides. The enzyme does not catalyse the glucosylation of the 5-hydroxy group of cyanidin 3-glucoside.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 70248-66-7

References:

1. Kamsteeg, J., van Brederode, J. and van Nigtevecht, G. Identification, properties, and genetic control of UDP-glucose: cyanidin-3-rhamnosyl-(1→6)-glucoside-5-O-glucosyltransferase isolated from petals of the red campion (Silene dioica). Biochem. Genet. 16 (1978) 1059-1071. [PMID: 751641]

2. Yabuya, T., Yamaguchi, M., Imayama, T., Katoh, K. and Ino I. Anthocyanin 5-O-glucosyltransferase in flowers of Iris ensata. Plant Sci. 162 (2002) 779-784.

3. Imayama, T., Yoshihara, Y., Fukuchi-Mizutani, M., Tanaka, Y., Ino, I. and Yabuya, T. Isolation and characterization of a cDNA clone of UDP-glucose:anthocyanin 5-O-glucosyltransferase in Iris hollandica. Plant Sci. 167 (2004) 1243-1248.

[EC 2.4.1.116 created 1984 (EC 2.4.1.235 created 2004, incorporated 2006), modified 2006, modified 2013]

EC 2.1.1.117

Accepted name: (S)-scoulerine 9-O-methyltransferase

Reaction: S-adenosyl-L-methionine + (S)-scoulerine = S-adenosyl-L-homocysteine + (S)-tetrahydrocolumbamine

For diagram click here.

Systematic name: S-adenosyl-L-methionine:(S)-scoulerine 9-O-methyltransferase

Comments: the product of this reaction is a precursor for protoberberine alkaloids in plants

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 96380-65-3

References:

1. Muemmler, S., Rueffer, M., Nagakura, N., Zenk, M.H. S-Adenosyl-L-methionine:(S)-scoulerine 9-O-methyltransferase, a highly stereo- and regiospecific enzyme in tetrahydroberberine biosynthesis. Plant Cell Reports 4 (1985) 36-39.

[EC 2.1.1.117 created 1999]

EC 2.1.1.118

Accepted name: columbamine O-methyltransferase

Reaction: S-adenosyl-L-methionine + columbamine = S-adenosyl-L-homocysteine + palmatine

For diagram click here.

Systematic name: S-adenosyl-L-methionine:columbamine O-methyltransferase

Comments: the product of this reaction is a protoberberine alkaloid that is widely distributed in the plant kingdom. This enzyme is distinct in specificity from EC 2.1.1.88, 8-hydroxyquercetin 8-O-methyltransferase.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 105843-76-3

References:

1. Rueffer, M., Amann, M., Zenk, M.H. S-Adenosyl-L-methionine:columbamine O-methyltransferase, a compartmentalized enzyme in protoberberine biosynthesis. Plant Cell Reports 3 (1986) 182-185.

[EC 2.1.1.118 created 1999]

EC 2.1.1.119

Accepted name: 10-hydroxydihydrosanguinarine 10-O-methyltransferase

Reaction: S-adenosyl-L-methionine + 10-hydroxydihydrosanguinarine = S-adenosyl-L-homocysteine + dihydrochelirubine

For diagram click here.

Systematic name: S-adenosyl-L-methionine:10-hydroxydihydrosanguinarine 10-O-methyltransferase

Comments: this reaction is part of the pathway for synthesis of benzophenanthridine alkaloids in plants.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 144388-39-6

References:

1. De-Eknamkul, W., Tanahashi, T., Zenk, M.H. Enzymic 10-hydroxylation and 10-O-methylation of dihydrosanguinarine in Eschscholtzia. Phytochemistry 31 (1992) 2713-2717.

[EC 2.1.1.119 created 1999]

EC 2.1.1.120

Accepted name: 12-hydroxydihydrochelirubine 12-O-methyltransferase

Reaction: S-adenosyl-L-methionine + 12-hydroxydihydrochelirubine = S-adenosyl-L-homocysteine + dihydromacarpine

For diagram click here.

Systematic name: S-adenosyl-L-methionine:12-hydroxydihydrochelirubine 12-O-methyltransferase

Comments: this reaction is part of the pathway for synthesis of benzophenanthridine alkaloid macarpine in plants.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 158736-40-4

References:

1. Kammerer, L., De-Eknamkul, W., Zenk, M.H. Enzymic 12-hydroxylation and 12-O-methylation of dihydrochelirubine in dihydromacarpine formation by Thalictrum bulgaricum. Phytochemistry 36 (1994) 1409-1416.

[EC 2.1.1.120 created 1999]

EC 2.1.1.121

Accepted name: 6-O-methylnorlaudanosoline 5'-O-methyltransferase

Reaction: S-adenosyl-L-methionine + 6-O-methylnorlaudanosoline = S-adenosyl-L-homocysteine + nororientaline

Systematic name: S-adenosyl-L-methionine:6-O-methylnorlaudanosoline 5'-O-methyltransferase

Comments: nororientaline is a precursor of the alkaloid papaverine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 89511-99-9

References:

1. Rueffer, M., Nagakura, N., Zenk, M.H. A highly specific O-methyltransferase for nororientaline synthesis isolated from Argemone platyceras cell cultures. Planta Med. 49 (1983) 196-198.

[EC 2.1.1.121 created 1999]

EC 2.1.1.122

Accepted name: (S)-tetrahydroprotoberberine N-methyltransferase

Reaction: S-adenosyl-L-methionine + (S)-7,8,13,14-tetrahydroprotoberberine = S-adenosyl-L-homocysteine + cis-N-methyl-(S)-7,8,13,14-tetrahydroprotoberberine

For diagram click here or here or click here.

Other name(s): tetrahydroprotoberberine cis-N-methyltransferase

Systematic name: S-adenosyl-L-methionine:(S)-7,8,13,14-tetrahydroprotoberberine cis-N-methyltransferase

Comments: involved in the biosynthesis of isoquinoline alkaloids in plants.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 106878-42-6

References:

1. Rueffer, M., Zumstein, G., Zenk, M.H. Partial purification and characterization of S-adenosyl-L-methionine:(S)-tetrahydroprotoberberine cis-N-methyltransferase from suspension-cultured cells of Eschscholtzia and Corydalis. Phytochemistry 29 (1990) 3727-3733.

[EC 2.1.1.122 created 1999]

EC 2.1.1.123

Accepted name: [cytochrome-c]-methionine S-methyltransferase

Reaction: S-adenosyl-L-methionine + [cytochrome c]-methionine = S-adenosyl-L-homocysteine + [cytochrome c]-S-methyl-methionine

Systematic name: S-adenosyl-L-methionine:[cytochrome c]-methionine S-methyltransferase

Comments: the enzyme from Euglena gracilis methylates Met-65 of horse heart cytochrome c.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 93585-98-9

References:

1. Farooqui, J.Z., Tuck, M., Paik, W.K. Purification and characterization of enzymes from Euglena gracilis that methylate methionine and arginine residues of cytochrome c. J. Biol. Chem. 260 (1985) 537-545. [PMID: 2981218]

[EC 2.1.1.123 created 1999]

[EC 2.1.1.124 Deleted entry: [cytochrome c]-arginine N-methyltransferase. Now covered by EC 2.1.1.319, type I protein arginine methyltransferase, EC 2.1.1.320, type II protein arginine methyltransferase, EC 2.1.1.321, type III protein arginine methyltransferase and EC 2.1.1.322, type IV protein arginine methyltransferase (EC 2.1.1.124 created 1999 (EC 2.1.1.23 created 1972, modified 1976, modified 1983, part incorporated 1999), deleted 2015)]

[EC 2.1.1.125 Deleted entry: histone-arginine N-methyltransferase. Now covered by EC 2.1.1.319, type I protein arginine methyltransferase, EC 2.1.1.320, type II protein arginine methyltransferase, EC 2.1.1.321, type III protein arginine methyltransferase and EC 2.1.1.322, type IV protein arginine methyltransferase (EC 2.1.1.125 created 1999 (EC 2.1.1.23 created 1972, modified 1976, modified 1983, part incorporated 1999), deleted 2015)]

[EC 2.1.1.126 Deleted entry: [myelin basic protein]-arginine N-methyltransferase. Now covered by EC 2.1.1.319, type I protein arginine methyltransferase, EC 2.1.1.320, type II protein arginine methyltransferase, EC 2.1.1.321, type III protein arginine methyltransferase and EC 2.1.1.322, type IV protein arginine methyltransferase (EC 2.1.1.126 created 1999 (EC 2.1.1.23 created 1972, modified 1976, modified 1983, part incorporated 1999), deleted 2015)]

EC 2.1.1.127

Accepted name: [ribulose-bisphosphate carboxylase]-lysine N-methyltransferase

Reaction: 3 S-adenosyl-L-methionine + [ribulose-1,5-bisphosphate carboxylase]-L-lysine = 3 S-adenosyl-L-homocysteine + [ribulose-1,5-bisphosphate carboxylase]-N6,N6,N6-trimethyl-L-lysine

Other name(s): rubisco methyltransferase; ribulose-bisphosphate-carboxylase/oxygenase N-methyltransferase; ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit εN-methyltransferase; S-adenosyl-L-methionine:[3-phospho-D-glycerate-carboxy-lyase (dimerizing)]-lysine 6-N-methyltransferase; RuBisCO methyltransferase; RuBisCO LSMT

Systematic name: S-adenosyl-L-methionine:[3-phospho-D-glycerate-carboxy-lyase (dimerizing)]-lysine N6-methyltransferase

Comments: The enzyme catalyses three successive methylations of Lys-14 in the large subunits of hexadecameric higher plant ribulose-bisphosphate-carboxylase (EC 4.1.1.39). Only the three methylated form is observed [3]. The enzyme from pea (Pisum sativum) also three-methylates a specific lysine in the chloroplastic isoforms of fructose-bisphosphate aldolase (EC 4.1.2.13) [5].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 139171-98-5

References:

1. Wang, P., Royer, M., Houtz, R.L. Affinity purification of ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit εN-methyltransferase. Protein Expr. Purif. 6 (1995) 528-536. [PMID: 8527940]

2. Ying, Z., Janney, N., Houtz, R.L. Organization and characterization of the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit N-methyltransferase gene in tobacco. Plant Mol. Biol. 32 (1996) 663-672. [PMID: 8980518]

3. Dirk, L.M., Flynn, E.M., Dietzel, K., Couture, J.F., Trievel, R.C. and Houtz, R.L. Kinetic manifestation of processivity during multiple methylations catalyzed by SET domain protein methyltransferases. Biochemistry 46 (2007) 3905-3915. [PMID: 17338551]

4. Magnani, R., Nayak, N.R., Mazarei, M., Dirk, L.M. and Houtz, R.L. Polypeptide substrate specificity of PsLSMT. A set domain protein methyltransferase. J. Biol. Chem. 282 (2007) 27857-27864. [PMID: 17635932]

5. Mininno, M., Brugiere, S., Pautre, V., Gilgen, A., Ma, S., Ferro, M., Tardif, M., Alban, C. and Ravanel, S. Characterization of chloroplastic fructose 1,6-bisphosphate aldolases as lysine-methylated proteins in plants. J. Biol. Chem. 287 (2012) 21034-21044. [PMID: 22547063]

[EC 2.1.1.127 created 1999, modified 2012]

EC 2.1.1.128

Accepted name: (RS)-norcoclaurine 6-O-methyltransferase

Reaction: S-adenosyl-L-methionine + (RS)-norcoclaurine = S-adenosyl-L-homocysteine + (RS)-coclaurine

For diagram click here.

Glossary:
Norcoclaurine: 6,7-dihydroxy-1-[(4-hydroxyphenyl)methyl]-1,2,3,4-tetrahydroisoquinoline

Systematic name: S-adenosyl-L-methionine:(RS)-norcoclaurine 6-O-methyltransferase

Comments: the enzyme will also catalyse the 6-O-methylation of (RS)-norlaudanosoline to form 6-O-methyl-norlaudanosoline, but this alkaloid has not been found to occur in plants.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 89700-33-4

References:

1. Rueffer, M., Nagakura, N., Zenk, M.H. Partial purification and properties of S-adenosyl-L-methionine:(R),(S)-norlaudanosoline-6-O-methyltransferase from Argemone platyceras cell cultures. Planta Med. 49 (1983) 131-137.

2. Sato, F., Tsujita, T., Katagiri, Y., Yoshida, S., Yamada, Y. Purification and characterization of S-adenosyl-L-methionine:norcoclaurine-6-O-methyltransferase from cultured Coptis japonica cells. Eur. J. Biochem. 225 (1994) 125-131. [PMID: 7925429]

3. Stadler, R., Zenk, M.H. A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline. Liebigs Ann. Chem. (1990) 555-562.

[EC 2.1.1.128 created 1999]

EC 2.1.1.129

Accepted name: inositol 4-methyltransferase

Reaction: S-adenosyl-L-methionine + myo-inositol = S-adenosyl-L-homocysteine + 1D-4-O-methyl-myo-inositol

For diagram click here.

Other name(s): myo-inositol 4-O-methyltransferase; S-adenosyl-L-methionine:myo-inositol 4-O-methyltransferase; myo-inositol 6-O-methyltransferase

Systematic name: S-adenosyl-L-methionine:1D-myo-inositol 4-methyltransferase

Comments: The enzyme from the rice bean Vigna umbellata (Fabaceae) is highly specific for S-adenosyl-L-methionine. The enzyme also methylates 1L-1,2,4/3,5-cyclohexanepentol, 2,4,6/3,5-pentahydroxycyclohexanone, D,L-2,3,4,6/5-pentacyclohexanone and 2,2'-anhydro-2-C-hydroxymethyl-myo-inositol, but at lower rates than that of myo-inositol.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 169277-48-9

References:

1. Vernon, D.M., Bohnert, H.J. A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum. EMBO J. 11 (1992) 2077-2085. [PMID: 1600940]

2. Wanek, W. and Richter, A. Purification and characterization of myo-inositol 6-O-methyltransferase from Vigna umbellata Ohwi et Ohashi. Planta 197 (1995) 427-434.

[EC 2.1.1.129 created 1999 (EC 2.1.1.134 created 1999, incorporated 2002), modified 2002]

EC 2.1.1.130

Accepted name: precorrin-2 C20-methyltransferase

Reaction: S-adenosyl-L-methionine + precorrin-2 = S-adenosyl-L-homocysteine + precorrin-3A

For diagram click here.

Systematic name: S-adenosyl-L-methionine:precorrin-2 C20-methyltransferase

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 131554-12-6

References:

1. Roessner, C.A., Warren, M.J., Santander, P.J., Atshaves, B.P., Ozaki, S., Stolowich, N.J., Iida, K., Scott, A.I. Expression of Salmonella typhimurium enzymes for cobinamide synthesis. Identification of the 11-methyl and 20-methyl transferases of corrin biosynthesis. FEBS Lett. 301 (1992) 73-78. [PMID: 1451790]

2. Roessner, C.A., Spencer, J.B., Ozaki, S., Min, C., Atshaves, B.P., Nayar, P., Anousis, N., Stolowich, N.J., Holderman, M.T., Scott, A.I. Overexpression in Escherichia coli of 12 vitamin B12 biosynthetic enzymes. Protein Extr. Purif. 6 (1995) 155-163. [PMID: 7606163]

3. Debussche, L., Thibaut, D., Cameron, B., Crouzet, J., Blanche, F.J. Biosynthesis of the corrin macrocycle of coenzyme B12 in Pseudomonas denitrificans. J. Bacteriol. 175 (1993) 7430-7440. [PMID: 8226690]

[EC 2.1.1.130 created 1999]

EC 2.1.1.131

Accepted name: precorrin-3B C17-methyltransferase

Reaction: S-adenosyl-L-methionine + precorrin-3B = S-adenosyl-L-homocysteine + precorrin-4

For diagram click here and mechanism (here).

Other name(s): precorrin-3 methyltransferase; CobJ

Systematic name: S-adenosyl-L-methionine:precorrin-3B C17-methyltransferase

Comments: In the aerobic cobalamin biosythesis pathway, four enzymes are involved in the conversion of precorrin-3A to precorrin-6A. The first of the four steps is carried out by EC 1.14.13.83, precorrin-3B synthase (CobG), yielding precorrin-3B as the product. This is followed by three methylation reactions, which introduce a methyl group at C-17 (CobJ; EC 2.1.1.131), C-11 (CobM; EC 2.1.1.133) and C-1 (CobF; EC 2.1.1.152) of the macrocycle, giving rise to precorrin-4, precorrin-5 and precorrin-6A, respectively.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 152787-64-9

References:

1. Scott, A.I., Roessner, C.A., Stolowich, N.J., Spencer, J.B., Min, C., Ozaki, S.I. Biosynthesis of vitamin B12. Discovery of the enzymes for oxidative ring contraction and insertion of the fourth methyl group. FEBS Lett. 331 (1993) 105-108. [PMID: 8405386]

2. Debussche, L., Thibaut, D., Cameron, B., Crouzet, J., Blanche, F.J. Biosynthesis of the corrin macrocycle of coenzyme B12 in Pseudomonas denitrificans. J. Bacteriol. 175 (1993) 7430-7440. [PMID: 8226690]

[EC 2.1.1.131 created 1999]

EC 2.1.1.132

Accepted name: precorrin-6B C5,15-methyltransferase (decarboxylating)

Reaction: 2 S-adenosyl-L-methionine + precorrin-6B = 2 S-adenosyl-L-homocysteine + precorrin-8X + CO2 (overall reaction)
(1a) S-adenosyl-L-methionine + precorrin-6B = S-adenosyl-L-homocysteine + precorrin-7 + CO2
(1b) S-adenosyl-L-methionine + precorrin-7 = S-adenosyl-L-homocysteine + precorrin-8X

For diagram of reaction click here and mechanism (click here).

Glossary: precorrin-6B = precorrin-6Y

Other name(s): precorrin-6 methyltransferase; precorrin-6Y methylase; precorrin-6Y C5,15-methyltransferase (decarboxylating); cobL (gene name)

Systematic name: S-adenosyl-L-methionine:1-precorrin-6B C5,15-methyltransferase (C-12-decarboxylating)

Comments: The enzyme, which participates in the aerobic adenosylcobalamin biosynthesis pathway, has S-adenosyl-L-methionine-dependent methyltransferase and decarboxylase activities. The enzyme is a fusion protein with two active sites; one catalyses the methylation at C15 and the decarboxylation, while the other catalyses the methylation at C5.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 162995-22-4

References:

1. Blanche, F., Famechon, A., Thibaut, D., Debussche, L., Cameron, B., Crouzet, J. Biosynthesis of vitamin B12 in Pseudomonas denitrificans: the biosynthetic sequence from precorrin-6Y to precorrin-8X is catalyzed by the cobL gene product. J. Bacteriol. 174 (1992) 1050-1052. [PMID: 1732195]

2. Deery, E., Schroeder, S., Lawrence, A.D., Taylor, S.L., Seyedarabi, A., Waterman, J., Wilson, K.S., Brown, D., Geeves, M.A., Howard, M.J., Pickersgill, R.W. and Warren, M.J. An enzyme-trap approach allows isolation of intermediates in cobalamin biosynthesis. Nat. Chem. Biol. 8 (2012) 933-940. [PMID: 23042036]

[EC 2.1.1.132 created 1999, modified 2013]

EC 2.1.1.133

Accepted name: precorrin-4 C11-methyltransferase

Reaction: S-adenosyl-L-methionine + precorrin-4 = S-adenosyl-L-homocysteine + precorrin-5

For diagram click here.

Other name(s): precorrin-3 methylase; CobM

Systematic name: S-adenosyl-L-methionine:precorrin-4 C11 methyltransferase

Comments: In the aerobic cobalamin biosythesis pathway, four enzymes are involved in the conversion of precorrin-3A to precorrin-6A. The first of the four steps is carried out by EC 1.14.13.83, precorrin-3B synthase (CobG), yielding precorrin-3B as the product. This is followed by three methylation reactions, which introduce a methyl group at C-17 (CobJ; EC 2.1.1.131), C-11 (CobM; EC 2.1.1.133) and C-1 (CobF; EC 2.1.1.152) of the macrocycle, giving rise to precorrin-4, precorrin-5 and precorrin-6A, respectively.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 152787-65-0

References:

1. Crouzet, J., Cameron, B., Cauchois, L., Rigault, S., Rouyez, M.C., Blanche, F., Thibaut D., Debussche, L. Genetic and sequence analysis of an 8.7-kilobase Pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid. J. Bacteriol. 172 (1990) 5980-5990. [PMID: 2211521]

2. Roth, J.R., Lawrence, J.G., Rubenfield, M., Kieffer-Higgins, S., Church, G.M. Characterization of the cobalamin (vitamin B12) biosynthetic genes of Salmonella typhimurium. J. Bacteriol. 175 (1993) 3303-3316. [PMID: 8501034]

[EC 2.1.1.133 created 1999]

[EC 2.1.1.134 Deleted entry: myo-inositol 6-O-methyltransferase. Now included with EC 2.1.1.129, inositol 4-methyltransferase (EC 2.1.1.134 created 1999, deleted 2002)]

[EC 2.1.1.135 Transferred entry: now EC 1.16.1.8 [methionine synthase] reductase. (EC 2.1.1.135 created 1999, deleted 2003)]

EC 2.1.1.136

Accepted name: chlorophenol O-methyltransferase

Reaction: S-adenosyl-L-methionine + trichlorophenol = S-adenosyl-L-homocysteine + trichloroanisole

Other name(s): halogenated phenol O-methyltransferase, trichlorophenol O-methyltransferase

Systematic name: S-adenosyl-L-methionine:trichlorophenol O-methyltransferase

Comments: The enzyme from Trichoderma virgatum, when cultured in the presence of halogenated phenol, also acts on a range of mono-, di- and trichlorophenols.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 196414-37-6

References:

1. Kikuchi, T. and Oe, T. Halogenated phenol O-methyltransferase, its production and deodorization using the same. Patent JP9234062, 1997. Chem. Abstr. 127 (1994) 274684.

[EC 2.1.1.136 created 2000]

EC 2.1.1.137

Accepted name: arsenite methyltransferase

Reaction: (1) S-adenosyl-L-methionine + arsenite = S-adenosyl-L-homocysteine + methylarsonate

(2) S-adenosyl-L-methionine + methylarsonite = S-adenosyl-L-homocysteine + dimethylarsinate

For diagram click here.

Other name(s): S-adenosyl-L-methionine:arsenic(III) methyltransferase; S-adenosyl-L-methionine:methylarsonite As-methyltransferase; methylarsonite methyltransferase

Systematic name: S-adenosyl-L-methionine:arsenite As-methyltransferase

Comments: An enzyme of the biotransformation pathway that forms dimethylarsinate from inorganic arsenite and arsenate. It methylates arsenite to form methylarsonate, Me-AsO3H2, which is reduced by EC 1.20.4.2, methylarsonate reductase, to methylarsonite, Me-As(OH)2. Methylarsonite is also a substrate for this enzyme (EC 2.1.1.137), which converts it into the much less toxic compound dimethylarsinate (cacodylate), Me2As(O)-OH.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, UM-BBD, CAS registry number: 167140-41-2

References:

1. Zakharyan, R.A. and Aposhian, H.V. Enzymatic reduction of arsenic compounds in mammalian systems: The rate-limiting enzyme of rabbit liver arsenic biotransformation is MMA(V) reductase. Chem. Res. Toxicol. 121 (1999) 1278-1283. [PMID: 10604879]

2. Zakharyan, R.A., Ayala-Fierro, F., Cullen, W.R., Carter, D.M. and Aposhian, H.V. Enzymatic methylation of arsenic compounds. VII. Monomethylarsonous acid (MMAIII) is the substrate for MMA methyltransferase of rabbit liver and human hepatocytes. Toxicol. Appl. Pharmacol. 158 (1999) 9-15. [PMID: 10387927]

3. Zakharyan, R.A., Wildfang, E. and Aposhian, H.V. Enzymatic methylation of arsenic compounds. III. The marmoset and tamarin, but not the rhesus, monkeys are deficient in methyltransferases that methylate inorganic arsenic. Toxicol. Appl. Pharmacol. 140 (1996) 77-84. [PMID: 8806872]

4. Zakharyan, R.A., Wu, Y., Bogdan, G.M. and Aposhian, H.V. Enzymatic methylation of arsenic compounds: assay, partial purification, and properties of arsenite methyltransferase and monomethylarsonic acid methyltransferase of rabbit liver. Chem. Res. Toxicol. 8 (1995) 1029-1038. [PMID: 8605285]

5. Lin, S., Shi, Q., Nix, F.B., Styblo, M., Beck, M.A., Herbin-Davis, K.M., Hall, L.L., Simeonsson, J.B. and Thomas, D.J. A novel S-adenosyl-L-methionine:arsenic(III) methyltransferase from rat liver cytosol. J. Biol. Chem. 277 (2002) 10795-10803. [PMID: 11790780]

[EC 2.1.1.137 created 2000, (EC 2.1.1.138 incorporated 2003), modified 2003]

[EC 2.1.1.138 Deleted entry: methylarsonite methyltransferase. Reaction due to EC 2.1.1.137, methylarsonite methyltransferase. (EC 2.1.1.138 created 2000, deleted 2003)]

EC 2.1.1.139

Accepted name: 3'-demethylstaurosporine O-methyltransferase

Reaction: S-adenosyl-L-methionine + 3'-demethylstaurosporine = S-adenosyl-L-homocysteine + staurosporine

Other name(s): 3'-demethoxy-3'-hydroxystaurosporine O-methyltransferase; staurosporine synthase

Systematic name: S-adenosyl-L-methionine:3'-demethylstaurosporine O-methyltransferase

Comments: Catalyses the final step in the biosynthesis of staurosporine, an alkaloidal antibiotic that is a potent inhibitor of protein kinases, especially protein kinase C.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 212906-74-6

References:

1. Weidner, S., Kittelmann, M., Goeke, K., Ghisalba, O. and Zahner, H. 3'-Demethoxy-3'-hydroxystaurosporine-O-methyltransferase from Streptomyces longisporoflavus catalyzing the last step in the biosynthesis of staurosporine. J. Antibiot. (Tokyo) 51 (1998) 679-682. [PMID: 9727395]

[EC 2.1.1.139 created 2000]

EC 2.1.1.140

Accepted name: (S)-coclaurine-N-methyltransferase

Reaction: S-adenosyl-L-methionine + (S)-coclaurine = S-adenosyl-L-homocysteine + (S)-N-methylcoclaurine

For diagram click here.

Systematic name: S-adenosyl-L-methionine:(S)-coclaurine-N-methyltransferase

Comments: The enzyme is specific for the (S)-isomer of coclaurine. Norcoclaurine can also act as an acceptor.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 167398-06-3

References:

1. Loeffler, S., Deus-Neumann, B. and Zenk, M.H. S-Adenosyl-L-methionine: (S)-coclaurine-N-methyltransferase from Tinospora cordifolia. Phytochemistry 38 (1995) 1387-1395.

[EC 2.1.1.140 created 2001]

EC 2.1.1.141

Accepted name: jasmonate O-methyltransferase

Reaction: S-adenosyl-L-methionine + jasmonate = S-adenosyl-L-homocysteine + methyl jasmonate

Glossary entries:
jasmonic acid = {(1R,2R)-3-oxo-2-[(Z)pent-2-enyl]cyclopent-2-enyl}acetic acid.

Other name(s): jasmonic acid carboxyl methyltransferase

Systematic name: S-adenosyl-L-methionine:jasmonate O-methyltransferase

Comments: 9,10-Dihydrojasmonic acid is a poor substrate for the enzyme. The enzyme does not convert 12-oxo-phytodienoic acid (a precursor of jasmonic acid), salicylic acid, benzoic acid, linolenic acid or cinnamic acid into their corresponding methyl esters. Enzyme activity is inhibited by the presence of divalent cations, e.g., Ca2+, Cu2+, Mg2+ and Zn2+.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 346420-58-4

References:

1. Seo, H.S., Song, J.T., Cheong, J.J., Lee, Y.H., Lee, Y.W., Hwang, I., Lee, J.S. and Choi, Y.D. Jasmonic acid carboxyl methyltransferase: A key enzyme for jasmonate-regulated plant responses. Proc. Natl. Acad. Sci. USA 98 (2001) 4788-4793. [PMID: 11287667]

[EC 2.1.1.141 created 2001]

EC 2.1.1.142

Accepted name: cycloartenol 24-C-methyltransferase

Reaction: S-adenosyl-L-methionine + cycloartenol = S-adenosyl-L-homocysteine + (24R)-24-methylcycloart-25-en-3β-ol

For diagram click here.

Other names: sterol C-methyltransferase

Systematic name: S-adenosyl-L-methionine:cycloartenol 24-C-methyltransferase

Comments S-Adenosyl-L-methionine methylates the Si face of the 24(25)-double bond with elimination of a hydrogen atom from the pro-Z methyl group at C-25.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 50936-46-4

References:

1. Mangla, A.T. and Nes, W.D. Sterol C-methyl transferase from Prototheca wickerhamii mechanism, sterol specificity and inhibition. Bioorg. Med. Chem. 8 (2000) 925-36. [PMID: 10882005]

[EC 2.1.1.142 created 2001]

EC 2.1.1.143

Accepted name: 24-methylenesterol C-methyltransferase

Reaction: S-adenosyl-L-methionine + 24-methylenelophenol = S-adenosyl-L-homocysteine + (Z)-24-ethylidenelophenol

For diagram click here.

Glossary:
lophenol = 4α-methyl-5α-cholesta-7-en-3β-ol

Other names: SMT2; 24-methylenelophenol C-241-methyltransferase

Systematic name: S-adenosyl-L-methionine:24-methylenelophenol C-methyltransferase

Comments: This is the second methylation step of plant sterol biosynthesis (cf EC 2.1.1.142, cycloartenol 24-C-methyltransferase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 67165-89-3

References:

1. Bouvier-Navé, P., Husselstein, T. and Benveniste, P. Two families of sterol methyltransferases are involved in the first and the second methylation steps of plant biosynthesis. Eur. J. Biochem. 256 (1998) 88-96. [PMID: 9746350]

[EC 2.1.1.143 created 2001]

EC 2.1.1.144

Accepted name: trans-aconitate 2-methyltransferase

Reaction: S-adenosyl-L-methionine + trans-aconitate = S-adenosyl-L-homocysteine + (E)-3-(methoxycarbonyl)pent-2-enedioate

For diagram click here.

Glossary:
trans-aconitate = (E)-prop-1-ene-1,2,3-tricarboxylate

Systematic name: S-adenosyl-L-methionine:(E)-prop-1-ene-1,2,3-tricarboxylate 2'-O-methyltransferase

Comments: Also catalyses the formation of the methyl monoester of cis-aconitate, isocitrate and citrate, but more slowly. While the enzyme from Escherichia coli forms (E)-3-(methoxycarbonyl)-pent-2-enedioate as the product, that from Saccharomyces cerevisiae forms (E)-2-(methoxycarbonylmethyl)butenedioate and is therefore classified as a separate enzyme (cf. EC 2.1.1.145, trans-aconitate 3-methyltransferase).

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 235107-12-7 (same as EC 2.1.1.145)

References:

1. Cai, H. and Clarke, S. A novel methyltransferase catalyzes the esterification of trans-aconitate in Escherichia coli. J. Biol. Chem. 274 (1999) 13470-13479. [PMID: 10224113]

2. Cai, H., Strouse, J., Dumlao, D., Jung, M.E. and Clarke, S. Distinct reactions catalyzed by bacterial and yeast trans-aconitate methyltransferase. Biochemistry 40 (2001) 2210-2219. [PMID: 11329290]

3. Cai, H., Dumlao, D., Katz, J.E. and Clarke, S. Identification of the gene and characterization of the activity of the trans-aconitate methyltransferase from Saccharomyces cerevisiae. Biochemistry 40 (2001) 13699-13709. [PMID: 11695919]

[EC 2.1.1.144 created 2002]

EC 2.1.1.145

Accepted name: trans-aconitate 3-methyltransferase

Reaction: S-adenosyl-L-methionine + trans-aconitate = S-adenosyl-L-homocysteine + (E)-2-(methoxycarbonylmethyl)butenedioate

For diagram click here.

Glossary:
trans-aconitate = (E)-prop-1-ene-1,2,3-tricarboxylate

Systematic name: S-adenosyl-L-methionine:(E)-prop-1-ene-1,2,3-tricarboxylate 3'-O-methyltransferase

Comments: Also catalyses the formation of the methyl monoester of cis-aconitate, isocitrate and citrate, but more slowly. While the enzyme from Saccharomyces cerevisiae forms (E)-2-(methoxycarbonylmethyl)butenedioate as the product, that from Escherichia coli forms (E)-3-(methoxycarbonyl)-pent-2-enedioate and is therefore classified as a separate enzyme (cf. EC 2.1.1.144, trans-aconitate 2-methyltransferase)

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 235107-12-7 (same as EC 2.1.1.144)

References:

1. Cai, H. and Clarke, S. A novel methyltransferase catalyzes the esterification of trans-aconitate in Escherichia coli. J. Biol. Chem. 274 (1999) 13470-13479. [PMID: 10224113]

2. Cai, H., Strouse, J., Dumlao, D., Jung, M.E. and Clarke, S. Distinct reactions catalyzed by bacterial and yeast trans-aconitate methyltransferase. Biochemistry 40 (2001) 2210-2219. [PMID: 11329290]

[EC 2.1.1.145 created 2002]

EC 2.1.1.146

Accepted name: (iso)eugenol O-methyltransferase

Reaction: S-adenosyl-L-methionine + isoeugenol = S-adenosyl-L-homocysteine + isomethyleugenol

For diagram click here.

Systematic name: S-adenosyl-L-methionine:isoeugenol O-methyltransferase

Comments: Acts on eugenol and chavicol as well as isoeugenol.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 191744-33-9

References:

1. Wang, J. and Pichersky, E. Characterization of S-adenosyl-L-methionine:(iso)eugenol O-methyltransferase involved in floral scent production in Clarkia breweri. Arch. Biochem. Biophys. 349 (1998) 153-160 [PMID: 9439593]

2. Gang, D.R., Lavid, N., Zubieta, C., Chen, F., Beuerle, T., Lewinsohn, E., Noel, J.P. and Pichersky, E. Characterization of phenylpropene O-methyltransferases from sweet basil: facile change of substrate specificity and convergent evolution within a plant O-methyltransferase family. Plant Cell 14 (2002) 505-519 [PMID: 11884690]

[EC 2.1.1.146 created 2002]

EC 2.1.1.147

Accepted name: corydaline synthase

Reaction: S-adenosyl-L-methionine + palmatine + 2 NADPH + H+ = S-adenosyl-L-homocysteine + corydaline + 2 NADP+

For diagram click here.

Systematic name: S-adenosyl-L-methionine:protoberberine 13-C-methyltransferase

Comments: Also acts on 7,8-dihydropalmatine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 155807-67-3

References:

1. Rueffer, M., Bauer, W. and Zenk, M.H. The formation of corydaline and related alkaloids in Corydalis cava in vivo and in vitro. Canad. J. Chem. 72 (1994) 170-175.

[EC 2.1.1.147 created 2002]

EC 2.1.1.148

Accepted name: thymidylate synthase (FAD)

Reaction: 5,10-methylenetetrahydrofolate + dUMP + NADPH + H+ = dTMP + tetrahydrofolate + NADP+

For diagram of reaction click here.

Other name(s): Thy1; ThyX

Systematic name: 5,10-methylenetetrahydrofolate,FADH2:dUMP C-methyltransferase

Comments: Contains FAD. All thymidylate synthases catalyse a reductive methylation involving the transfer of the methylene group of 5,10-methylenetetrahydrofolate to the C5-position of dUMP and a two electron reduction of the methylene group to a methyl group. Unlike the classical thymidylate synthase, ThyA (EC 2.1.1.45), which uses folate as both a 1-carbon donor and a source of reducing equivalents, this enzyme uses a flavin coenzyme as a source of reducing equivalents, which are derived from NADPH.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 850167-13-4

References:

1. Myllykallio, H., Lipowski, G., Leduc, D., Filee, J., Forterre, P. and Liebl, U. An alternative flavin-dependent mechanism for thymidylate synthesis. Science 297 (2002) 105-107. [PMID: 12029065]

2. Griffin, J., Roshick, C., Iliffe-Lee, E. and McClarty, G. Catalytic mechanism of Chlamydia trachomatis flavin-dependent thymidylate synthase. J. Biol. Chem. 280 (2005) 5456-5467. [PMID: 15591067]

3. Graziani, S., Bernauer, J., Skouloubris, S., Graille, M., Zhou, C.Z., Marchand, C., Decottignies, P., van Tilbeurgh, H., Myllykallio, H. and Liebl, U. Catalytic mechanism and structure of viral flavin-dependent thymidylate synthase ThyX. J. Biol. Chem. 281 (2006) 24048-24057. [PMID: 16707489]

4. Koehn, E.M., Fleischmann, T., Conrad, J.A., Palfey, B.A., Lesley, S.A., Mathews, I.I. and Kohen, A. An unusual mechanism of thymidylate biosynthesis in organisms containing the thyX gene. Nature 458 (2009) 919-923. [PMID: 19370033]

5. Koehn, E.M. and Kohen, A. Flavin-dependent thymidylate synthase: a novel pathway towards thymine. Arch. Biochem. Biophys. 493 (2010) 96-102. [PMID: 19643076]

[EC 2.1.1.148 created 2003, modified 2010]

[EC 2.1.1.149 Deleted entry: myricetin O-methyltransferase. Now covered by EC 2.1.1.267, flavonoid 3',5'-methyltransferase. (EC 2.1.1.149 created 2003, modified 2011, deleted 2013)]

EC 2.1.1.150

Accepted name: isoflavone 7-O-methyltransferase

Reaction: S-adenosyl-L-methionine + a 7-hydroxyisoflavone = S-adenosyl-L-homocysteine + a 7-methoxyisoflavone

See diagram for reaction in prunetin or isoformononetin biosynthesis.

For diagram click here.

Other name(s):

Systematic name: S-adenosyl-L-methionine:hydroxyisoflavone 7-O-methyltransferase

Comments: The enzyme from alfalfa can methylate daidzein, genistein and 6,7,4'-trihydroxyisoflavone but not flavones or flavanones.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 136111-54-1

References:

1. Edwards, R. and Dixon, R.A. Isoflavone O-methyltransferase activities in elicitor-treated cell suspension cultures of Medicago sativa. Phytochemistry 30 (1991) 2597-2606.

2. He, X.Z. and Dixon, R.A. Genetic manipulation of isoflavone 7-O-methyltransferase enhances biosynthesis of 4'-O-methylated isoflavonoid phytoalexins and disease resistance in alfalfa. Plant Cell 12 (2000) 1689-1702. [PMID: 11006341]

3. He, X.-Z. and Dixon, R.A. Affinity chromatography, substrate/product specificity, and amino acid sequence analysis of an isoflavone O-methyltransferase from alfalfa (Medicago sativa L.). Arch. Biochem. Biophys. 336 (1996) 121-129. [PMID: 8951042]

4. He, X.Z., Reddy, J.T. and Dixon, R.A. Stress responses in alfalfa (Medicago sativa L). XXII. cDNA cloning and characterization of an elicitor-inducible isoflavone 7-O-methyltransferase. Plant Mol. Biol. 36 (1998) 43-54. [PMID: 9484461]

5. Liu, C.-J. and Dixon, R.A. Elicitor-induced association of isoflavone O-methyltransferase with endomembranes prevents the formation and 7-O-methylation of daidzein during isoflavonoid phytoalexin biosynthesis. Plant Cell 13 (2001) 2643-2658. [PMID: 11752378]

6. Zubieta, C., He, X.-Z., Dixon, R.A. and Noel, J.P. Structures of two natural product methyltransferases reveal the basis for substrate specificity in plant O-methyltransferases. Nat. Struct. Biol. 8 (2001) 271-279. [PMID: 11224575]

[EC 2.1.1.150 created 2003]


Continued with EC 2.1.1.151 to EC 2.1.1.200
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