The core domain of Aquifex aeolicus tRNA (m7G46) methyltransferase has the methyl-transfer activity to tRNA.
Transfer RNA (m(7)G46) methyltransferase [TrmB] catalyses the transfer of methyl groups from S-adenosyl-L-methionine to the N(7)-atom of guanine at position 46 in tRNA. TrmB proteins from thermophilic bacteria such as Aquifex aeolicus have a long C-terminal region as compared to those from mesophilic bacteria. Further, N-terminal region observed in TrmB proteins from mesophiles is missing in A. aeolicus TrmB. Therefore, we considered that this distinct C-terminal region in A. aeolicus TrmB might compensate the N-terminal region in mesophile TrmB and function as a part of tRNA binding site. To confirm this idea, we deleted the C-terminal region by introduction of the stop codon at position 202. To our surprise, methyl-transfer assay using yeast tRNA(Phe) transcript clearly showed that the resultant mutant protein (Glu202Stop) had an enzymatic activity. Thus, the core domain of the A. aeolicus TrmB has a methyl-transfer activity.
Tomikawa
Chie
C
Graduate School of Materials and Biotechnology, Ehime University, Matsuyama 790-8577, Japan.
Hori
Hiroyuki
H
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation; D012343:RNA, Transfer / Q000378:metabolism; D012359:tRNA Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012343:RNA, Transfer; C474650:YggH protein, E coli; D012359:tRNA Methyltransferases