Specificity of tRNA-mRNA interactions in Bacillus subtilis tyrS antitermination.
The Bacillus subtilis tyrS gene, encoding tyrosyl-tRNA synthetase, is a member of the T-box family of genes, which are regulated by control of readthrough of a leader region transcriptional terminator. Readthrough is induced by interaction of the cognate uncharged tRNA with the leader; the system responds to decreased tRNA charging, caused by amino acid limitation or insufficient levels of the aminoacyl-tRNA synthetase. Recognition of the cognate tRNA is mediated by pairing of the anticodon of the tRNA with the specifier sequence of the leader, a codon specifying the appropriate amino acid; a second interaction between the acceptor end of the tRNA and an antiterminator structure is also important. Certain switches of the specifier sequence to a new codon result in a switch in the specificity of the amino acid response, while other switches do not. These effects may reflect additional sequence or structural requirements for the mRNA-tRNA interaction. This study includes investigation of the effects of a large number of specifier sequence switches in tyrS and analysis of structural differences between tRNA(Tyr) and tRNA species which interact inefficiently with the tyrS leader to promote antitermination.
Grundy
F J
FJ
Department of Microbiology, The Ohio State University, Columbus 43210, USA.
Hodil
S E
SE
Rollins
S M
SM
Henkin
T M
TM
D001412:Bacillus subtilis / Q000235:genetics*; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D012363:RNA, Transfer, Thr / Q000235:genetics; D012365:RNA, Transfer, Tyr / Q000235:genetics; D014448:Tyrosine-tRNA Ligase / Q000235:genetics*
D003062:Codon; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012363:RNA, Transfer, Thr; D012365:RNA, Transfer, Tyr; D012343:RNA, Transfer; D014448:Tyrosine-tRNA Ligase