PDF(Pubmed)
Abstract：
Most bacteria divide through a highly conserved process called binary fission, in which there is symmetric growth of daughter cells and the synthesis of peptidoglycan at the mid-cell to enable cytokinesis. During this process, the parental cell replicates its chromosomal DNA and segregates replicated chromosomes into the daughter cells. The mechanisms that regulate binary fission have been extensively studied in several model organisms, including Eschericia coli, Bacillus subtilis, and Caulobacter crescentus. These analyses have revealed that a multi-protein complex called the divisome forms at the mid-cell to enable peptidoglycan synthesis and septation during division. In addition, rod-shaped bacteria form a multi-protein complex called the elongasome that drives sidewall peptidoglycan synthesis necessary for the maintenance of rod shape and the lengthening of the cell prior to division. In adapting to their intracellular niche, the obligate intracellular bacteria discussed here have eliminated one to several of the divisome gene products essential for binary fission in E. coli. In addition, genes that encode components of the elongasome, which were mostly lost as rod-shaped bacteria evolved into coccoid organisms, have been retained during the reductive evolutionary process that some coccoid obligate intracellular bacteria have undergone. Although the precise molecular mechanisms that regulate the division of obligate intracellular bacteria remain undefined, the studies summarized here indicate that obligate intracellular bacteria exhibit remarkable plasticity in their cell division processes.
摘要：
大多数细菌通过一个高度保守的过程分裂，称为二元裂变，其中子细胞的对称生长和在中间细胞的肽聚糖的合成以实现胞质分裂。在这个过程中,亲代细胞复制其染色体DNA并将复制的染色体分离到子细胞中。调节二元裂变的机制已经在几种模式生物中得到了广泛的研究，包括大肠杆菌,枯草芽孢杆菌,和crescentus。这些分析揭示了称为分裂体的多蛋白复合物在中间细胞处形成，以使肽聚糖在分裂过程中合成和分离。此外,杆状细菌形成称为延伸体的多蛋白复合物，该复合物驱动维持杆状和分裂前细胞延长所需的侧壁肽聚糖合成。为了适应它们的细胞内生态位，这里讨论的专性细胞内细菌已经消除了大肠杆菌中二元裂变所必需的一个到几个分裂基因产物。此外,编码延伸体成分的基因，这些细菌大部分是随着杆状细菌进化成球形生物而丢失的，在某些球形专性细胞内细菌经历的还原进化过程中被保留。尽管调节专性细胞内细菌分裂的精确分子机制仍不明确，这里总结的研究表明，专性细胞内细菌在其细胞分裂过程中表现出显著的可塑性。
