Expression of both Bacillus subtilis threonyl-tRNA synthetase genes is autogenously regulated.

摘要: The "housekeeping" threonyl-tRNA synthetase gene (thrS) of Bacillus subtilis is shown to be transcribed in vivo and vitro from a single promoter. In vitro, 85% all messages the thrS promoter are terminated at strong factor-independent terminator localized upstream Shine-Dalgarno sequence, within 305-nucleotide-long leader region. Overexpression represses transcriptional translational thrS-lacZ fusions similar extent, suggesting that autoregulated level. We show autogenous control does not act level transcription initiation but involves antitermination mechanism. thrZ, second gene, also autogenously regulated. However, ability ThrS repress as well thrZ expression much greater than ThrZ synthetase.