Activities and regulation of peptidoglycan synthases.
Activities and regulation of peptidoglycan synthases.
复制标题
DOI：
10.1098/rstb.2015.0031
复制
发表时间：
2015-10-05
期刊：
影响因子：
--
通讯作者：
Vollmer W
中科院分区：
文献类型：
--
作者：
Egan AJ;Biboy J;van't Veer I;Breukink E;Vollmer W
肽聚糖（PG）是几乎所有细菌细胞壁的重要组成部分，在细胞质膜周围形成一个连续的网状结构，称为小囊，以保护细胞不因膨胀而破裂。尽管PG合成酶，即青霉素结合蛋白（PBPs），已经被研究了70年，但用于测量其活性的有用的体外测定方法直到最近才建立起来，并且这些方法首次提供了对这些酶的调控的见解。本文就PG合成酶的糖基转移酶和转肽酶活性的研究进展进行综述。我们提供的新数据表明，来自大肠杆菌的双功能PBP1A和PBP1B在重组到蛋白脂质体的膜环境时具有活性，并且这些酶在某些条件下也表现出dd -羧肽酶活性。这两个新特征都与它们在细胞内的功能有关。我们还回顾了最近关于蛋白质-蛋白质相互作用和其他因素对PBPs活性影响的数据。作为一个例子，我们证明了多种蛋白-蛋白相互作用对PBP1B糖基转移酶活性的协同作用，通过其同源脂蛋白激活剂LpoB和必需的细胞分裂蛋白FtsN。
Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have been studied for 70 years, useful in vitro assays for measuring their activities were established only recently, and these provided the first insights into the regulation of these enzymes. Here, we review the current knowledge on the glycosyltransferase and transpeptidase activities of PG synthases. We provide new data showing that the bifunctional PBP1A and PBP1B from Escherichia coli are active upon reconstitution into the membrane environment of proteoliposomes, and that these enzymes also exhibit DD-carboxypeptidase activity in certain conditions. Both novel features are relevant for their functioning within the cell. We also review recent data on the impact of protein–protein interactions and other factors on the activities of PBPs. As an example, we demonstrate a synergistic effect of multiple protein–protein interactions on the glycosyltransferase activity of PBP1B, by its cognate lipoprotein activator LpoB and the essential cell division protein FtsN.