title: Discrimination among E. coli tRNAs with a long variable arm.
abstract: In E. coli, tRNA(Ser), tRNA(Leu) and tRNA(Tyr) have a long variable arm composed of more than ten nucleotides (class II tRNAs). In order to study how leucyl- and seryl-tRNA synthetase discriminate their cognate tRNA isoacceptors from the other class II tRNAs, kinetic parameters of various mutated class II tRNA transcripts with leucyl- and seryl-tRNA synthetase were determined. Leucyl-tRNA synthetase recognizes A73 and A14 or its vicinity. Seryl-tRNA synthetase recognizes the long variable arm base-nonspecifically. C2-G71 in the acceptor stem functions as a negative identity element against seryl-tRNA synthetase. Difference in the tertiary structure among class II tRNA molecules plays a crucial role in discrimination by these two synthetases.
authors.affiliation: Institute of Space and Astronautical Science, Kanagawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Asahara
authors.forename: H
authors.initials: H
authors.lastname: Himeno
authors.forename: K
authors.initials: K
authors.lastname: Tamura
authors.forename: N
authors.initials: N
authors.lastname: Nameki
authors.forename: T
authors.initials: T
authors.lastname: Hasegawa
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
mesh_terms: D000215:Acylation; D004926:Escherichia coli / Q000235:genetics*; D007700:Kinetics; D007935:Leucine-tRNA Ligase / Q000737:chemistry; D009154:Mutation; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry*; D012362:RNA, Transfer, Ser / Q000737:chemistry*; D012365:RNA, Transfer, Tyr / Q000737:chemistry*; D012714:Serine-tRNA Ligase / Q000737:chemistry
chemical_list: D012329:RNA, Bacterial; D012362:RNA, Transfer, Ser; D012365:RNA, Transfer, Tyr; D012714:Serine-tRNA Ligase; D007935:Leucine-tRNA Ligase