Roels S, Driks A, Losick R
Department of Cellular and Developmental Biology Laboratories, Harvard University, Cambridge, Massachusetts 02138.
J Bacteriol. 1992 Jan;174(2):575-85. doi: 10.1128/jb.174.2.575-585.1992.
We report the cloning and characterization of the Bacillus subtilis sporulation locus spoIVA, mutations at which cause an unusual defect in spore formation in which the coat misassembles as swirls within the mother cell. We show that spoIVA is a single gene of 492 codons that is capable of encoding a polypeptide of 55 kDa. Transcription of spoIVA is induced at about the second hour of sporulation by the regulatory protein sigma E from two closely spaced promoters designated P1 and P2. Experiments in which the upstream promoter P1 was removed show that transcription of spoIVA from P2 is sufficient for efficient spore formation. Based on these and other findings, we infer that the spoIVA gene product is a morphogenetic protein; we discuss its role in the deposition of coat polypeptides around the developing forespore.
我们报道了枯草芽孢杆菌芽孢形成基因座spoIVA的克隆和特性分析，该基因发生突变会导致芽孢形成出现异常缺陷，即芽孢衣在母细胞内错误组装成漩涡状。我们发现spoIVA是一个由492个密码子组成的单基因，能够编码一个55 kDa的多肽。spoIVA的转录在芽孢形成约两小时时由调控蛋白σE从两个紧密相邻的启动子P1和P2诱导产生。去除上游启动子P1的实验表明，从P2转录spoIVA足以实现高效的芽孢形成。基于这些及其他发现，我们推断spoIVA基因产物是一种形态发生蛋白；我们讨论了它在发育中的前芽孢周围芽孢衣多肽沉积中的作用。
