Strauch M A, Wu J J, Jonas R H, Hoch J A
Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92027.
Mol Microbiol. 1993 Mar;7(6):967-74. doi: 10.1111/j.1365-2958.1993.tb01188.x.
The spo0F gene of Bacillus subtilis encodes a protein that functions as a secondary messenger in a phosphorelay system controlling the initiation of sporulation. Transcription of the spo0F gene was known to be dependent on an intact gene for the transcription regulator Spo0A. In vitro footprint analysis revealed that Spo0A protein bound to two locations in the spo0F promoter region. Deletion of a 40 bp region upstream of one of the promoters (P2) abolished the activation of spo0F expression that occurs at the onset of stationary phase and sporulation. This 40 bp region contains a Spo0A-binding site. These observations are consistent with a hypothesis that Spo0A binding to this region is responsible for activating spo0F transcription. Additionally, Spo0A binding at a downstream site could modulate the level of this activation. Since Spo0F protein is required for the formation of Spo0A-P (the form needed for transcriptional activation) a positive feedback loop controls transcription of spo0F.
枯草芽孢杆菌的spo0F基因编码一种蛋白质，该蛋白质在控制芽孢形成起始的磷酸传递系统中作为第二信使发挥作用。已知spo0F基因的转录依赖于转录调节因子Spo0A的完整基因。体外足迹分析表明，Spo0A蛋白与spo0F启动子区域的两个位点结合。其中一个启动子（P2）上游40 bp区域的缺失消除了在稳定期和芽孢形成开始时发生的spo0F表达激活。这个40 bp区域包含一个Spo0A结合位点。这些观察结果与一个假设一致，即Spo0A与该区域的结合负责激活spo0F转录。此外，Spo0A在下游位点的结合可以调节这种激活的水平。由于形成Spo0A-P（转录激活所需的形式）需要Spo0F蛋白，因此一个正反馈环控制着spo0F的转录。
