RRC ID 3958
著者 Purta E, O'Connor M, Bujnicki JM, Douthwaite S.
タイトル YccW is the m5C methyltransferase specific for 23S rRNA nucleotide 1962.
ジャーナル J Mol Biol
Abstract Methylation at the 5-position of cytosine [m(5)C (5-methylcytidine)] occurs at three RNA nucleotides in Escherichia coli. All these modifications are at highly conserved nucleotides in the rRNAs, and each is catalyzed by its own m(5)C methyltransferase enzyme. Two of the enzymes, RsmB and RsmF, are already known and methylate 16S rRNA at nucleotides C967 and C1407, respectively. Here, we report the identity of the third E. coli m(5)C methyltransferase. Analysis of rRNAs by matrix-assisted laser desorption/ionization mass spectrometry showed that inactivation of the yccW gene leads to loss of m(5)C methylation at nucleotide 1962 in E. coli 23S rRNA. This methylation is restored by complementing the knockout strain with a plasmid-encoded copy of the yccW gene. Purified recombinant YccW protein retains its specificity for C1962 in vitro and methylates naked 23S rRNA isolated from the yccW knockout strain. However, YccW does not methylate assembled 50S subunits, and this is somewhat surprising as the published crystal structures show nucleotide C1962 to be fully accessible at the subunit interface. YccW-directed methylation at nucleotide C1962 is conserved in bacteria, and loss of this methylation in E. coli marginally reduces its growth rate. YccW had previously eluded identification because it displays only limited sequence similarity to the m(5)C methyltransferases RsmB and RsmF and is in fact more similar to known m(5)U (5-methyluridine) RNA methyltransferases. In keeping with the previously proposed nomenclature system for bacterial rRNA methyltransferases, yccW is now designated as the rRNA large subunit methyltransferase gene rlmI.
巻・号 383(3)
ページ 641-51
公開日 2008-11-14
DOI 10.1016/j.jmb.2008.08.061
PII S0022-2836(08)01068-1
PMID 18786544
MeSH Amino Acid Sequence Base Sequence Escherichia coli / enzymology* Escherichia coli Proteins / chemistry Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism* Genetic Complementation Test Methylation Methyltransferases / chemistry Methyltransferases / genetics Methyltransferases / metabolism* Models, Molecular Molecular Sequence Data Nucleic Acid Conformation Nucleotides / chemistry Nucleotides / genetics Nucleotides / metabolism* Protein Structure, Tertiary RNA, Ribosomal, 23S / chemistry RNA, Ribosomal, 23S / genetics* RNA, Ribosomal, 23S / metabolism Sequence Alignment Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Substrate Specificity
IF 4.76
引用数 38
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌) ME9062 (BW25113)