Formation of m 2 G6 in Methanocaldococcus jannaschii tRNA catalyzed by the novel methyltransferase Trm14
Open Access
- 21 June 2011
- journal article
- research article
- Published by Oxford University Press (OUP) in Nucleic Acids Research
- Vol. 39 (17), 7641-7655
- https://doi.org/10.1093/nar/gkr475
Abstract
The modified nucleosides N 2 -methylguanosine and -dimethylguanosine in transfer RNA occur at five positions in the D and anticodon arms, and at positions G6 and G7 in the acceptor stem. Trm1 and Trm11 enzymes are known to be responsible for several of the D/anticodon arm modifications, but methylases catalyzing post-transcriptional m 2 G synthesis in the acceptor stem are uncharacterized. Here, we report that the MJ0438 gene from Methanocaldococcus jannaschii encodes a novel S -adenosylmethionine-dependent methyltransferase, now identified as Trm14, which generates m 2 G at position 6 in tRNA Cys . The 381 amino acid Trm14 protein possesses a canonical RNA recognition THUMP domain at the amino terminus, followed by a γ-class Rossmann fold amino-methyltransferase catalytic domain featuring the signature NPPY active site motif. Trm14 is associated with cluster of orthologous groups (COG) 0116, and most closely resembles the m 2 G10 tRNA methylase Trm11. Phylogenetic analysis reveals a canonical archaeal/bacterial evolutionary separation with 20–30% sequence identities between the two branches, but it is likely that the detailed functions of COG 0116 enzymes differ between the archaeal and bacterial domains. In the archaeal branch, the protein is found exclusively in thermophiles. More distantly related Trm14 homologs were also identified in eukaryotes known to possess the m 2 G6 tRNA modification.
Keywords
This publication has 62 references indexed in Scilit:
- Agmatidine, a modified cytidine in the anticodon of archaeal tRNA Ile , base pairs with adenosine but not with guanosineProceedings of the National Academy of Sciences, 2010
- Stereochemical mechanisms of tRNA methyltransferasesFEBS Letters, 2009
- Do all modifications benefit all tRNAs?FEBS Letters, 2009
- Aquifex aeolicus tRNA (N2,N2-Guanine)-dimethyltransferase (Trm1) Catalyzes Transfer of Methyl Groups Not Only to Guanine 26 but Also to Guanine 27 in tRNAJournal of Biological Chemistry, 2009
- Redundant Synthesis of Cysteinyl-tRNACys in Methanosarcina mazeiJournal of Biological Chemistry, 2008
- The Homotetrameric Phosphoseryl-tRNA Synthetase from Methanosarcina mazei Exhibits Half-of-the-sites ActivityJournal of Biological Chemistry, 2008
- Distinct Determinants of tRNA Recognition by the TrmD and Trm5 Methyl TransferasesJournal of Molecular Biology, 2007
- THUMP from archaeal tRNA:m22G10 methyltransferase, a genuine autonomously folding domainNucleic Acids Research, 2006
- Multiple sequence alignment with the Clustal series of programsNucleic Acids Research, 2003
- Gapped BLAST and PSI-BLAST: a new generation of protein database search programsNucleic Acids Research, 1997