Reaction: 2 S-adenosyl-L-methionine + G(5')pppAACA-[mRNA] = 2 S-adenosyl-L-homocysteine + m7G(5')pppAmACA-[mRNA] (overall reaction)
(1a) S-adenosyl-L-methionine + G(5')pppAACA-[mRNA] = S-adenosyl-L-homocysteine + G(5')pppAmACA-[mRNA]
(1b) S-adenosyl-L-methionine + G(5')pppAmACA-[mRNA] = S-adenosyl-L-homocysteine + m7G(5')pppAmACA-[mRNA]
Systematic name: S-adenosyl-L-methionine:G(5')pppAACA-[mRNA] N7,2'-O-methyltransferase
Comments: The enzyme from non-segmented negative strain (NNS) viruses (e.g. rhabdoviruses) catalyses two successive methylations. In higher eukaryotes the two methylations occur in the reverse order and are catalysed by two different enzymes (cf. EC 2.1.1.56, mRNA (guanine-N7)-methyltransferase, and EC 2.1.1.57, methyltransferase cap1) that do not required a specific motif.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Rahmeh, A.A., Li, J., Kranzusch, P.J. and Whelan, S.P. Ribose 2'-O methylation of the vesicular stomatitis virus mRNA cap precedes and facilitates subsequent guanine-N-7 methylation by the large polymerase protein. J. Virol. 83 (2009) 11043-11050. [PMID: 19710136]