title: Distinct tRNA recognition strategies used by a homologous family of editing domains prevent mistranslation.
abstract: Errors in protein synthesis due to mispairing of amino acids with tRNAs jeopardize cell viability. Several checkpoints to prevent formation of Ala- and Cys-tRNA(Pro) have been described, including the Ala-specific editing domain (INS) of most bacterial prolyl-tRNA synthetases (ProRSs) and an autonomous single-domain INS homolog, YbaK, which clears Cys-tRNA(Pro) in trans. In many species where ProRS lacks an INS domain, ProXp-ala, another single-domain INS-like protein, is responsible for editing Ala-tRNA(Pro). Although the amino acid specificity of these editing domains has been established, the role of tRNA sequence elements in substrate selection has not been investigated in detail. Critical recognition elements for aminoacylation by bacterial ProRS include acceptor stem elements G72/A73 and anticodon bases G35/G36. Here, we show that ProXp-ala and INS require these same acceptor stem and anticodon elements, respectively, whereas YbaK lacks inherent tRNA specificity. Thus, these three related domains use divergent approaches to recognize tRNAs and prevent mistranslation. Whereas some editing domains have borrowed aspects of tRNA recognition from the parent aminoacyl-tRNA synthetase, relaxed tRNA specificity leading to semi-promiscuous editing may offer advantages to cells.
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA, Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA, Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA and Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
authors.forename: Mom
authors.initials: M
authors.lastname: Das
authors.forename: Oscar
authors.initials: O
authors.lastname: Vargas-Rodriguez
authors.forename: Yuki
authors.initials: Y
authors.lastname: Goto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suga
authors.forename: Karin
authors.initials: K
authors.lastname: Musier-Forsyth
mesh_terms: D000409:Alanine / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D000926:Anticodon; D002352:Carrier Proteins / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins / Q000378:metabolism; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012361:RNA, Transfer, Pro / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000926:Anticodon; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D012346:RNA, Transfer, Amino Acyl; D012361:RNA, Transfer, Pro; C584682:YbaK protein, E coli; D000604:Amino Acyl-tRNA Synthetases; C100134:prolyl T RNA synthetase; D003545:Cysteine; D000409:Alanine