論文

査読有り
2005年3月

Roles of conserved amino acid sequence motifs in the SpoU (TrmH) RNA methyltransferase family

JOURNAL OF BIOLOGICAL CHEMISTRY
  • K Watanabe
  • ,
  • O Nureki
  • ,
  • S Fukai
  • ,
  • R Ishii
  • ,
  • H Okamoto
  • ,
  • S Yokoyama
  • ,
  • Y Endo
  • ,
  • H Hori

280
11
開始ページ
10368
終了ページ
10377
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1074/jbc.M411209200
出版者・発行元
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Transfer RNA (Gm18) methyltransferase (TrmH (SpoU)) catalyzes the transfer of a methyl group from S-adenosyl- L-methionine (AdoMet) to the 2'-OH of guanosine 18 in tRNA. This enzyme is a member of the SpoU family of RNA methyltransferases. Recent computational researches have shown that three amino acid sequence motifs are conserved among the SpoU members. Recently, we determined the crystal structures of the apo- and AdoMet bound forms of TrmH (Nureki, O., Watanabe, K., Fukai, S., Ishii, R., Endo, Y., Hori, H., and Yokoyama, S. (2004) Structure 12, 593-602). Furthermore, we clarified the AdoMet binding site and proposed the catalytic mechanism. Since the functions of the conserved amino acid residues in the motifs remain unknown, here we have prepared 17 mutants of TrmH and carried out various biochemical studies, including determination of the kinetic parameters for both AdoMet and tRNA, S-adenosyl- L-homocysteine affinity chromatography, gel mobility shift assay, CD spectroscopy, and analytical gel filtration. Our results show that Asn(35), Arg(41), Glu(124), and Asn(152) are involved in binding tRNA and that the Asn(35) residue is involved in the release of S-adenosyl- L-homocysteine. Several residues of TrmH are important for stability of the enzyme. Taken together, our biochemical studies reinforce the previously proposed catalytic mechanism. We also discuss amino acid substitutions in general within the SPOUT superfamily of methyltransferases.

Web of Science ® 被引用回数 : 53

リンク情報
DOI
https://doi.org/10.1074/jbc.M411209200
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000227559600077&DestApp=WOS_CPL

エクスポート
BibTeX RIS