Qi F X, He X S, Doi R H
Department of Biochemistry and Biophysics, University of California, Davis 95616.
J Bacteriol. 1991 Nov;173(21):7050-4. doi: 10.1128/jb.173.21.7050-7054.1991.
The sigA operon of Bacillus subtilis is transcribed from at least two SigA and two SigH promoters. Primer extension and promoter probe analyses have localized a fifth promoter, P5, that is active only at later sporulation stages (T3 to T5). Mutations in the genes for the sigma factors SigG, SigK, SigH, and SigE do not block transcription from P5. The expression from P5 is blocked or severely reduced in spo0A, spo0B, spo0E, and spo0K mutants.
枯草芽孢杆菌的sigA操纵子至少从两个SigA启动子和两个SigH启动子转录。引物延伸和启动子探针分析定位了第五个启动子P5，它仅在芽孢形成后期（T3至T5）具有活性。σ因子SigG、SigK、SigH和SigE基因中的突变不会阻断P5的转录。在spo0A、spo0B、spo0E和spo0K突变体中，P5的表达被阻断或严重降低。
