Reaction: 4 S-adenosyl-L-methionine + guanine26/guanine27 in tRNA = 4 S-adenosyl-L-homocysteine + N2-dimethylguanine26/N2-dimethylguanine27 in tRNA
Other name(s): Trm1 (ambiguous); tRNA (N2,N2-guanine)-dimethyltransferase; tRNA (m2(2G26) methyltransferase; Trm1[tRNA (m2(2)G26) methyltransferase]
Systematic name: S-adenosyl-L-methionine:tRNA (guanine26-N2/guanine27-N2)-dimethyltransferase
Comments: The enzyme from Aquifex aeolicus is similar to the TRM1 methyltransferases of archaea and eukarya (see EC 18.104.22.168, tRNA (guanine26-N2)-dimethyltransferase). However, it catalyses the double methylation of guanines at both positions 26 and 27 of tRNA.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
1. Awai, T., Kimura, S., Tomikawa, C., Ochi, A., Ihsanawati, Bessho, Y., Yokoyama, S., Ohno, S., Nishikawa, K., Yokogawa, T., Suzuki, T. and Hori, H. Aquifex aeolicus tRNA (N2,N2-guanine)-dimethyltransferase (Trm1) catalyzes transfer of methyl groups not only to guanine 26 but also to guanine 27 in tRNA. J. Biol. Chem. 284 (2009) 20467-20478. [PMID: 19491098]