Wang P Z, Doi R H
J Biol Chem. 1984 Jul 10;259(13):8619-25.
A 471-base pair HindIII DNA fragment of Bacillus subtilis contains two overlapping promoters which are recognized in vitro by sigma 55- and sigma 37-containing RNA polymerase holoenzymes from B. subtilis. In vitro transcript analyses and S1 nuclease mapping experiments with in vivo RNA indicate that both enzymes initiate transcription from the same putative +1 site. Physiological studies with the promoter-containing DNA fragment inserted into the expression probe plasmid pCED6 and quantitative S1 nuclease mapping experiments with RNA isolated from various stages of growth indicate that expression from these overlapping promoters is greater during the early stationary phase than during growth. We propose that the cryptic gene controlled by these promoters is transcribed by the sigma 55 enzyme during growth and by the sigma 37 enzyme during early stationary phase.
枯草芽孢杆菌的一个471碱基对的HindIII DNA片段包含两个重叠启动子，枯草芽孢杆菌中含σ55和含σ37的RNA聚合酶全酶在体外可识别这两个启动子。体外转录分析和用体内RNA进行的S1核酸酶作图实验表明，这两种酶均从同一个假定的+1位点起始转录。将含启动子的DNA片段插入表达探针质粒pCED6进行的生理学研究，以及对从不同生长阶段分离的RNA进行的定量S1核酸酶作图实验表明，这些重叠启动子在生长早期的表达高于生长期间。我们提出，由这些启动子控制的隐蔽基因在生长期间由σ55酶转录，在生长早期由σ37酶转录。
