tRNA as a positive regulator of transcription antitermination in B. subtilis.
Most Bacillus tRNA synthetase genes are regulated by a common transcription antitermination mechanism but respond individually to limitation for the cognate amino acid. The mRNA leader regions of these genes exhibit extensive structural conservation, with a single codon specific for the appropriate amino acid at the identical position in each structure. Alteration of this sequence in the tyrS gene from UAC (tyrosine) to UUC (phenylalanine) resulted in loss of induction by tyrosine limitation and a switch to induction by phenylalanine limitation. Insertion of an extra base immediately upstream of the codon did not alter regulation, indicating a nontranslational mechanism. A nonsense codon resulted in an uninducible phenotype that was suppressible in a lysyl-tRNA nonsense suppressor mutant, indicating that tRNA acts as an effector.
Grundy
F J
FJ
Department of Biochemistry and Molecular Biology, Albany Medical College, New York 12208.
Henkin
T M
TM
D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D017124:Conserved Sequence; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D005838:Genotype; D008961:Models, Structural; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010652:Phenylalanine-tRNA Ligase / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D012343:RNA, Transfer / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic; D014448:Tyrosine-tRNA Ligase / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D012333:RNA, Messenger; D011994:Recombinant Proteins; D012343:RNA, Transfer; D001616:beta-Galactosidase; D000604:Amino Acyl-tRNA Synthetases; D014448:Tyrosine-tRNA Ligase; D010652:Phenylalanine-tRNA Ligase