Schuch R, Piggot P J
Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
J Bacteriol. 1994 Jul;176(13):4104-10. doi: 10.1128/jb.176.13.4104-4110.1994.
The spoIIA operon of Bacillus subtilis encodes sigma F and two proteins that may regulate sigma factor activity. High level induction of the tricistronic spoIIA operon occurs early during spore formation. At later times, the locus is cotranscribed with the upstream gene dacF, which encodes a putative DD-carboxypeptidase. In this study, the regulation of dacF-spoIIA transcription has been analyzed. Expression of a dacF-lacZ transcriptional fusion during sporulation required sigma F but not the later-expressed sporulation-associated sigma factors. Induction of sigma F synthesis during vegetative growth caused expression of dacF-lacZ fusions. The dacF-spoIIA promoter sequence is similar to sequences of previously identified sigma F promoters. It is concluded that dacF-spoIIA is transcribed by E sigma F. We present evidence that dacF-spoIIA is also transcribed by E sigma G, as is the case for the three other promoters known to be transcribed by E sigma F.
枯草芽孢杆菌的spoIIA操纵子编码σF以及两种可能调控σ因子活性的蛋白质。三顺反子spoIIA操纵子的高水平诱导在芽孢形成早期发生。在芽孢形成后期，该基因座与上游基因dacF一起被共转录，dacF编码一种假定的DD-羧肽酶。在本研究中，对dacF-spoIIA转录的调控进行了分析。芽孢形成过程中dacF-lacZ转录融合体的表达需要σF，但不需要后期表达的与芽孢形成相关的σ因子。在营养生长期间诱导σF合成会导致dacF-lacZ融合体的表达。dacF-spoIIA启动子序列与先前鉴定的σF启动子序列相似。得出的结论是，dacF-spoIIA由EσF转录。我们提供证据表明，dacF-spoIIA也由EσG转录，已知由EσF转录的其他三个启动子也是如此。
