Centre for Bacterial Cell Biology, Baddiley-Clark Building, Medical School, Newcastle University, Richardson Road, Newcastle Upon Tyne, NE2 4AX, United Kingdom
Curr Opin Microbiol. 2014 Dec;22:94-101. doi: 10.1016/j.mib.2014.09.020.
Division site selection presents a fundamental challenge to all organisms. Bacterial cells are small and the chromosome (nucleoid) often fills most of the cell volume. Thus, in order to maximise fitness and avoid damaging the genetic material, cell division must be tightly co-ordinated with chromosome replication and segregation. To achieve this, bacteria employ a number of different mechanisms to regulate division site selection. One such mechanism, termed nucleoid occlusion, allows the nucleoid to protect itself by acting as a template for nucleoid occlusion factors, which prevent Z-ring assembly over the DNA. These factors are sequence-specific DNA-binding proteins that exploit the precise organisation of the nucleoid, allowing them to act as both spatial and temporal regulators of bacterial cell division. The identification of proteins responsible for this process has provided a molecular understanding of nucleoid occlusion but it has also prompted the realisation that substantial levels of redundancy exist between the diverse systems that bacteria employ to ensure that division occurs in the right place, at the right time.
分裂位点的选择是所有生物都面临的一个基本挑战。细菌细胞很小，染色体（类核）通常占据细胞体积的大部分。因此，为了最大限度地提高适应性并避免遗传物质受损，细胞分裂必须与染色体复制和分离紧密协调。为了实现这一点，细菌采用了许多不同的机制来调节分裂位点的选择。其中一种机制称为类核封闭，允许类核通过充当类核封闭因子的模板来保护自身，这些因子阻止 Z 环在 DNA 上组装。这些因子是序列特异性 DNA 结合蛋白，它们利用类核的精确组织，使它们能够作为细菌细胞分裂的空间和时间调节剂。负责这一过程的蛋白质的鉴定提供了对类核封闭的分子理解，但也促使人们意识到，细菌用来确保在正确的时间和地点进行分裂的不同系统之间存在大量冗余。
