2ztg
From Proteopedia
Crystal structure of Archaeoglobus fulgidus alanyl-tRNA synthetase lacking the C-terminal dimerization domain in complex with Ala-SA
Structural highlights
FunctionSYA_ARCFU Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala-AMP and then transferred to the acceptor end of tRNA(Ala). Incorrectly charged aminoacyl-tRNA(Ala) is also edited in situ by the editing domain.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAlanyl-tRNA synthetase (AlaRS) specifically recognizes the major identity determinant, the G3:U70 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 G3:U70 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. Unique protein architecture of alanyl-tRNA synthetase for aminoacylation, editing, and dimerization.,Naganuma M, Sekine S, Fukunaga R, Yokoyama S Proc Natl Acad Sci U S A. 2009 May 26;106(21):8489-94. Epub 2009 May 7. PMID:19423669[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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