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Unique protein architecture of alanyl-tRNA synthetase for aminoacylation, editing, and dimerization.
Naganuma, Masahiro; Sekine, Shun-ichi; Fukunaga, Ryuya; Yokoyama, Shigeyuki.
Afiliação
  • Naganuma M; Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Proc Natl Acad Sci U S A ; 106(21): 8489-94, 2009 May 26.
Article em En | MEDLINE | ID: mdl-19423669
ABSTRACT
Alanyl-tRNA synthetase (AlaRS) specifically recognizes the major identity determinant, the G3U70 base pair, in the acceptor stem of tRNA(Ala) by both the tRNA-recognition and editing domains. In this study, we solved the crystal structures of 2 halves of Archaeoglobus fulgidus AlaRS AlaRS-DeltaC, comprising the aminoacylation, tRNA-recognition, and editing domains, and AlaRS-C, comprising the dimerization domain. The aminoacylation/tRNA-recognition domains contain an insertion incompatible with the class-specific tRNA-binding mode. The editing domain is fixed tightly via hydrophobic interactions to the aminoacylation/tRNA-recognition domains, on the side opposite from that in threonyl-tRNA synthetase. A groove formed between the aminoacylation/tRNA-recognition domains and the editing domain appears to be an alternative tRNA-binding site, which might be used for the aminoacylation and/or editing reactions. Actually, the amino acid residues required for the G3U70 recognition are mapped in this groove. The dimerization domain consists of helical and globular subdomains. The helical subdomain mediates dimerization by forming a helix-loop-helix zipper. The globular subdomain, which is important for the aminoacylation and editing activities, has a positively-charged face suitable for tRNA binding.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Alanina-tRNA Ligase / Multimerização Proteica Idioma: En Revista: Proc Natl Acad Sci U S A Ano de publicação: 2009 Tipo de documento: Article País de afiliação: Japão

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Alanina-tRNA Ligase / Multimerização Proteica Idioma: En Revista: Proc Natl Acad Sci U S A Ano de publicação: 2009 Tipo de documento: Article País de afiliação: Japão