Rothfield L, Justice S, García-Lara J
Department of Microbiology, University of Connecticut Health Center, Farmington 06032, USA.
Annu Rev Genet. 1999;33:423-48. doi: 10.1146/annurev.genet.33.1.423.
Formation of the bacterial division septum is catalyzed by a number of essential proteins that assemble into a ring structure at the future division site. Assembly of proteins into the cytokinetic ring appears to occur in a hierarchial order that is initiated by the FtsZ protein, a structural and functional analog of eukaryotic tubulins. Placement of the division site at its correct location in Escherichia coli requires a division inhibitor (MinC), that is responsible for preventing septation at unwanted sites near the cell poles, and a topological specificity protein (MinE), that forms a ring at midcell and protects the midcell site from the division inhibitor. However, the mechanism responsible for identifying the position of the midcell site or the polar sites used for spore septum formation is still unclear. Regulation of the division process and its coordination with other cell cycle events, such as chromosome replication, are poorly understood. However, a protein has been identified in Caulobacter (CtrA) that regulates both the initiation of chromosome regulation and the transcription of ftsZ, and that may play an important role in the coordination process.
细菌分裂隔膜的形成由多种必需蛋白质催化，这些蛋白质在未来的分裂位点组装成环形结构。蛋白质组装到细胞分裂环中似乎是按照层次顺序发生的，这一过程由FtsZ蛋白启动，FtsZ蛋白是真核微管蛋白的结构和功能类似物。在大肠杆菌中，将分裂位点定位在正确位置需要一种分裂抑制剂（MinC），它负责防止在细胞两极附近的非预期位点形成隔膜，还需要一种拓扑特异性蛋白（MinE），它在细胞中部形成一个环，并保护细胞中部位点免受分裂抑制剂的影响。然而，负责识别细胞中部位点或用于孢子隔膜形成的极位点位置的机制仍不清楚。对分裂过程的调控及其与其他细胞周期事件（如染色体复制）的协调了解甚少。然而，在柄杆菌属（CtrA）中已鉴定出一种蛋白质，它既调节染色体调控的起始，又调节ftsZ的转录，并且可能在协调过程中发挥重要作用。
