title: A single base substitution in the variable pocket of yeast tRNA(Arg) eliminates species-specific aminoacylation.
abstract: Early biochemical data showed that aminoacyl-tRNA synthetases often displayed species-specific recognition of tRNA. We compared the ability of purified Saccharomyces cerevisiae and Escherichia coli arginyl-tRNA synthetases to aminoacylate native and transcribed yeast tRNA(Arg) as well as E. coli tRNA(Arg). The kinetic data revealed that yeast ArgRS could charge E. coli tRNA(Arg), but at a lower efficiency than it charged either the transcribed or native yeast tRNA(Arg). E. coli ArgRS can acylate only its cognate E. coli tRNA. Strikingly, a single base change from C to A at position 20 in yeast tRNA(3)(Arg) altered the species specificity. The transcript of yeast tRNA(3)(Arg)CA20 mutant was aminoacylated by E. coli ArgRS with a 10(6) increase in k(cat)/K(m) over that for aminoacylation of yeast tRNA(3)(Arg) transcript. This indicates that A20 is not only an important identity of E. coli tRNA(Arg), but is also the key to altering species-specific aminoacylation of yeast tRNA(Arg).
authors.affiliation: State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, 320 Yue-yang Road, Shanghai, China.
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.forename: G
authors.initials: G
authors.lastname: Eriani
authors.forename: J
authors.initials: J
authors.lastname: Gangloff
authors.forename: E
authors.initials: E
authors.lastname: Wang
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005798:Genes, Bacterial; D005800:Genes, Fungal; D007700:Kinetics; D017354:Point Mutation; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D013379:Substrate Specificity / Q000235:genetics*; D013698:Templates, Genetic; D014158:Transcription, Genetic
chemical_list: D012346:RNA, Transfer, Amino Acyl; D000604:Amino Acyl-tRNA Synthetases