Discrimination among E. coli tRNAs with a long variable arm.
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.
Asahara
H
H
Institute of Space and Astronautical Science, Kanagawa, Japan.
Himeno
H
H
Tamura
K
K
Nameki
N
N
Hasegawa
T
T
Shimizu
M
M
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
D012329:RNA, Bacterial; D012362:RNA, Transfer, Ser; D012365:RNA, Transfer, Tyr; D012714:Serine-tRNA Ligase; D007935:Leucine-tRNA Ligase