論文

査読有り
2004年11月

Substrate tRNA recognition mechanism of tRNA (m(7)G46) methyltransferase from Aquifex aeolicus

JOURNAL OF BIOLOGICAL CHEMISTRY
  • H Okamoto
  • ,
  • K Watanabe
  • ,
  • Y Ikeuchi
  • ,
  • T Suzuki
  • ,
  • Y Endo
  • ,
  • H Hori

279
47
開始ページ
49151
終了ページ
49159
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1074/jbc.M408209200
出版者・発行元
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Transfer RNA (m(7)G46) methyltransferase catalyzes the methyl transfer from S-adenosylmethionine to N-7 atom of the guanine 46 residue in tRNA. Analysis of the Aquifex aeolicus genome revealed one candidate open reading frame, aq065, encoding this gene. The aq065 protein was expressed in Escherichia coli and purified to homogeneity on 15% SDS-polyacrylamide gel electrophoresis. Although the overall amino acid sequence of the aq065 protein differs considerably from that of E. coli YggH, the purified aq065 protein possessed a tRNA (m(7)G46) methyltransferase activity. The modified nucleoside and its location were determined by liquid chromatography-mass spectroscopy. To clarify the RNA recognition mechanism of the enzyme, we investigated the methyl transfer activity to 28 variants of yeast tRNA(Phe) and E. coli tRNA(Thr). It was confirmed that 5'-leader and 3'-trailer RNAs of tRNA precursor are not required for the methyl transfer. We found that the enzyme specificity was critically dependent on the size of the variable loop. Experiments using truncated variants showed that the variable loop sequence inserted between two stems is recognized as a substrate, and the most important recognition site is contained within the T stem. These results indicate that the L-shaped tRNA structure is not required for methyl acceptance activity. It was also found that nucleotide substitutions around G46 in three-dimensional core decrease the activity.

Web of Science ® 被引用回数 : 43

リンク情報
DOI
https://doi.org/10.1074/jbc.M408209200
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000225098100080&DestApp=WOS_CPL

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