IUBMB Enzyme Nomenclature

EC 2.1.1.57

Accepted name: methyltransferase cap1

Reaction: S-adenosyl-L-methionine + a 5'-(N7-methyl 5'-triphosphoguanosine)-(purine-ribonucleotide)-[mRNA] = S-adenosyl-L-homocysteine + a 5'-(N7-methyl 5'-triphosphoguanosine)-(2'-O-methyl-purine-ribonucleotide)-[mRNA]

Other name(s): messenger ribonucleate nucleoside 2'-methyltransferase; messenger RNA (nucleoside-2'-)-methyltransferase; MTR1; cap1-MTase; mRNA (nucleoside-2'-O)-methyltransferase (ambiguous); S-adenosyl-L-methionine:mRNA (nucleoside-2'-O)-methyltransferase

Systematic name: S-adenosyl-L-methionine:5-(N7-methyl 5-triphosphoguanosine)-(purine-ribonucleotide)-[mRNA] 2-O-methyltransferase

Comments: This enzyme catalyses the methylation of the ribose on the first transcribed nucleotide of mRNA or snRNA molecules, which may be either guanosine or adenosine. This methylation event is known as cap1, and occurrs in all mRNAs and snRNAs of higher eukaryotes, including insects, vertebrates and their viruses. The human enzyme can also methylate mRNA molecules that lack methylation on the capping 5'-triphosphoguanosine [6].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 61970-02-3

References:

1. Barbosa, E. and Moss, B. mRNA(nucleoside-2'-)-methyltransferase from vaccinia virus. Purification and physical properties. J. Biol. Chem. 253 (1978) 7692-7697. [PMID: 701281]

2. Barbosa, E. and Moss, B. mRNA(nucleoside-2'-)-methyltransferase from vaccinia virus. Characteristics and substrate specificity. J. Biol. Chem. 253 (1978) 7698-7702. [PMID: 701282]

3. Boone, R.F., Ensinger, M.J. and Moss, B. Synthesis of mRNA guanylyltransferase and mRNA methyltransferases in cells infected with vaccinia virus. J. Virol. 21 (1977) 475-483. [PMID: 833934]

4. Ensinger, M.J., Martin, S.A., Paoletti, E. and Moss, B. Modification of the 5'-terminus of mRNA by soluble guanylyl and methyl transferases from vaccinia virus. Proc. Natl. Acad. Sci. USA 72 (1975) 2525-2529. [PMID: 1058472]

5. Groner, Y., Gilbao, E. and Aviv, H. Methylation and capping of RNA polymerase II primary transcripts by HeLa nuclear homogenates. Biochemistry 17 (1978) 977-982. [PMID: 629955]

6. Werner, M., Purta, E., Kaminska, K.H., Cymerman, I.A., Campbell, D.A., Mittra, B., Zamudio, J.R., Sturm, N.R., Jaworski, J. and Bujnicki, J.M. 2'-O-ribose methylation of cap2 in human: function and evolution in a horizontally mobile family. Nucleic Acids Res. 39 (2011) 4756-4768. [PMID: 21310715]

[EC 2.1.1.57 created 1981 (EC 2.1.1.58 created 1981, incorporated 1984), modified 2014]


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