Constitutive septal murein synthesis in Escherichia coli with impaired activity of the morphogenetic proteins RodA and penicillin-binding protein 2
Constitutive septal murein synthesis in Escherichia coli with impaired activity of the morphogenetic proteins RodA and penicillin-binding protein 2
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DOI：
10.1128/jb.183.14.4115-4126.2001
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发表时间：
2001-07-01
影响因子：
3.2
通讯作者：
Schwarz, H
中科院分区：
文献类型：
--
作者：
de Pedro, MA;Donachie, WD;Schwarz, H
通过D-半胱氨酸-生物素免疫标记技术研究了形态发生蛋白青霉素结合蛋白2和RodA活性受损的大肠杆菌细胞中肽聚糖（胞壁蛋白）分离的模式（M. A. de Pedro，J. C. Quintela，J. V. Holtje和H.施瓦茨，J.细菌学。179：2823-2834，1997）。通过氨地西林处理或通过相应基因pbpA和rodA中的突变分别使这些蛋白失活，导致产生圆形的、遗传稳定的细胞。在正常的杆状细胞中，新的胞壁素前体以弥漫的方式遍布侧壁，与预先存在的物质均匀混合，除了在分隔期间，当严格局部化的胞壁素合成发生时。相反，在圆形细胞中，新前体的掺入显然是一个带状过程，定位于以前发生分裂的位置。因此，没有新的和旧的穆林混合。老穆兰在大而明确的地区保存了很长一段时间。我们建议，观察到的模式是一个失败的结果，关闭隔胞壁蛋白合成在分隔事件结束。此外，分离结果证实，rodA突变体的圆形细胞确实如先前提出的那样在交替的垂直平面中分裂。
The pattern of peptidoglycan (murein) segregation in cells of Escherichia coli with impaired activity of the morphogenetic proteins penicillin-binding protein 2 and RodA has been investigated by the D-cysteine-biotin immunolabeling technique (M. A. de Pedro, J. C. Quintela, J.-V. Holtje, and H. Schwarz, J. Bacteriol. 179:2823-2834, 1997). Inactivation of these proteins either by amdinocillin treatment or by mutations in the corresponding genes, pbpA and rodA, respectively, leads to the generation of round, osmotically stable cells. In normal rod-shaped cells, new murein precursors are incorporated all over the lateral wall in a diffuse manner, being mixed up homogeneously with preexisting material, except during septation, when strictly localized murein synthesis occurs. In contrast, in rounded cells, incorporation of new precursors is apparently a zonal process, localized at positions at which division had previously taken place. Consequently, there is no mixing of new and old murein. Old murein is preserved for long periods of time in large, well-defined areas. We propose that the observed patterns are the result of a failure to switch off septal murein synthesis at the end of septation events. Furthermore, the segregation results confirm that round cells of rodA mutants do divide in alternate, perpendicular planes as previously proposed.