Nucleic Acids Research Advance Access originally published online on April 17, 2008
Nucleic Acids Research 2008 36(10):3252-3262; doi:10.1093/nar/gkn169
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Nucleic Acids Research, 2008, Vol. 36, No. 10 3252-3262
© 2008 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Molecular Biology |
The YqfN protein of Bacillus subtilis is the tRNA: m1A22 methyltransferase (TrmK)
1Institut de Recherches Microbiologiques Jean-Marie Wiame, B-1070 Bruxelles, Belgium, 2Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Trojdena 4, PL-02-109 Warsaw, 3Bioinformatics Laboratory, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, PL-61-614 Poznan, 4Insitute of Technical Biochemistry, Technical University of Lodz, Stefanowskiego 4/10, PL-90-924 Lodz, Poland and 5Laboratoire de Microbiologie, Institut de Recherches Microbiologiques Jean-Marie Wiame, Université Libre de Bruxelles, B-1070 Bruxelles, Belgium
*To whom correspondence should be addressed. Tel: +48 22 597 0750; Fax: +48 22 597 0715; Email: iamb{at}genesilico.pl Correspondence may also be addressed to Louis Droogmans. Tel: +32 2 526 7715; Fax: +32 2 526 7273; Email: ldroogma{at}ulb.ac.be
Received December 23, 2007. Revised March 21, 2008. Accepted March 24, 2008.
N1-methylation of adenosine to m1A occurs in several different positions in tRNAs from various organisms. A methyl group at position N1 prevents Watson–Crick-type base pairing by adenosine and is therefore important for regulation of structure and stability of tRNA molecules. Thus far, only one family of genes encoding enzymes responsible for m1A methylation at position 58 has been identified, while other m1A methyltransferases (MTases) remain elusive. Here, we show that Bacillus subtilis open reading frame yqfN is necessary and sufficient for N1-adenosine methylation at position 22 of bacterial tRNA. Thus, we propose to rename YqfN as TrmK, according to the traditional nomenclature for bacterial tRNA MTases, or TrMet(m1A22) according to the nomenclature from the MODOMICS database of RNA modification enzymes. tRNAs purified from a 
trmK strain are a good substrate in vitro for the recombinant TrmK protein, which is sufficient for m1A methylation at position 22 as are tRNAs from Escherichia coli, which natively lacks m1A22. TrmK is conserved in Gram-positive bacteria and present in some Gram-negative bacteria, but its orthologs are apparently absent from archaea and eukaryota. Protein structure prediction indicates that the active site of TrmK does not resemble the active site of the m1A58 MTase TrmI, suggesting that these two enzymatic activities evolved independently.
The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors