Expression of both Bacillus subtilis threonyl-tRNA synthetase genes is autogenously regulated.
The "housekeeping" threonyl-tRNA synthetase gene (thrS) of Bacillus subtilis is shown to be transcribed in vivo and in vitro from a single promoter. In vitro, 85% of all messages transcribed from the thrS promoter are terminated at a strong factor-independent terminator localized upstream of the thrS Shine-Dalgarno sequence, within the 305-nucleotide-long leader region. Overexpression of thrS represses transcriptional and translational thrS-lacZ fusions to a similar extent, suggesting that thrS is autoregulated at the transcriptional level. We show that autogenous control does not act at the level of transcription initiation but involves antitermination of the transcription mechanism. thrZ, the second threonyl-tRNA synthetase gene, is also autogenously regulated. However, the ability of the ThrS synthetase to repress thrS as well as thrZ expression is much greater than that of the ThrZ synthetase.
Gendron
N
N
Service de Biochimie, Centre National de la Recherche Scientifique URA 1139, Institut de Biologie Physico-Chimique, Paris, France.
Putzer
H
H
Grunberg-Manago
M
M
D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D004794:Enzyme Repression / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D013914:Threonine-tRNA Ligase / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D014158:Transcription, Genetic
D007527:Isoenzymes; D011993:Recombinant Fusion Proteins; D013914:Threonine-tRNA Ligase