Yahashiri Atsushi, Jorgenson Matthew A, Weiss David S
Department of Microbiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
J Bacteriol. 2017 Jun 27;199(14). doi: 10.1128/JB.00118-17. Print 2017 Jul 15.
Sporulation-related repeat (SPOR) domains are small peptidoglycan (PG) binding domains found in thousands of bacterial proteins. The name "SPOR domain" stems from the fact that several early examples came from proteins involved in sporulation, but SPOR domain proteins are quite diverse and contribute to a variety of processes that involve remodeling of the PG sacculus, especially with respect to cell division. SPOR domains target proteins to the division site by binding to regions of PG devoid of stem peptides ("denuded" glycans), which in turn are enriched in septal PG by the intense, localized activity of cell wall amidases involved in daughter cell separation. This targeting mechanism sets SPOR domain proteins apart from most other septal ring proteins, which localize via protein-protein interactions. In addition to SPOR domains, bacteria contain several other PG-binding domains that can exploit features of the cell wall to target proteins to specific subcellular sites.
孢子形成相关重复(SPOR)结构域是在数千种细菌蛋白中发现的小肽聚糖(PG)结合结构域。“SPOR结构域”这个名称源于几个早期的例子来自参与孢子形成的蛋白质,但SPOR结构域蛋白种类繁多,有助于涉及PG囊泡重塑的各种过程,特别是在细胞分裂方面。SPOR结构域通过与不含茎肽的PG区域(“裸露”聚糖)结合,将蛋白质靶向到分裂位点,而这些区域又通过参与子细胞分离的细胞壁酰胺酶的强烈局部活性在隔膜PG中富集。这种靶向机制使SPOR结构域蛋白与大多数其他隔膜环蛋白不同,后者通过蛋白质-蛋白质相互作用进行定位。除了SPOR结构域,细菌还含有其他几种PG结合结构域,它们可以利用细胞壁的特征将蛋白质靶向到特定的亚细胞位点。