Mechanisms of cell growth, morphology, and maintenance by bacterial cell surface regulation

对枯草芽孢杆菌的两个细胞壁水解酶基因(cwlO和lyte)的分析表明，这两个基因产物定位于细胞的侧面，它们的自溶DL-内肽酶活性是细胞生长所必需的。核磁共振分析表明，ISEA是一种独特的具有锯齿状结构的蛋白质。为了维持细胞表面，稳定期和营养生长期分别需要SIGMA导向调节(SIGI和反SIGMA RsgI)和双组分系统Walk-WalR。此外，还研究了壁磷壁酸对肽聚糖的修饰，并报道了新型表面蛋白的酶性质。

Analysis of two cell wall hydrolase genes (cwlO and lytE) in Bacillus subtilisindicated that these two gene products were localized at the lateral side of cells and their autolytic DL-endopeptidase activity was required for cell growth. The activity is inhibited by IseA, and NMR analysis indicated IseA is a unique protein with a “hacksaw” structure. To maintain the cell surface, the sigma-directed regulation (SigI and anti-sigma RsgI) and the two-component system, WalK-WalR, were required at the stationary and vegetative growth phases, respectively. Peptidoglycan modification by wall teichoic acids was also investigated and the enzymatic properties of novel surface proteins were reported.