LytN, a Murein Hydrolase in the Cross-wall Compartment of Staphylococcus aureus, Is Involved in Proper Bacterial Growth and Envelope Assembly
LytN, a Murein Hydrolase in the Cross-wall Compartment of Staphylococcus aureus, Is Involved in Proper Bacterial Growth and Envelope Assembly
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DOI：
10.1074/jbc.m111.258863
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发表时间：
2011-09-16
影响因子：
4.8
通讯作者：
Schneewind, Olaf
中科院分区：
文献类型：
--
作者：
Frankel, Matthew B.;Hendrickx, Antoni P. A.;Schneewind, Olaf
球形微生物金黄色葡萄球菌的细胞周期进程需要肽聚糖的协调合成和重塑。大多数重排发生在中间细胞，在一个指定的横壁的隔室。被赋予YSIRK-G/S信号肽的分泌多肽被直接递送至跨壁区室。一种这样的含有YSIRK的蛋白质是胞壁酶水解酶LytN。lytN突变促使横壁结构损伤并干扰葡萄球菌生长。lytN的过表达也影响生长并触发横壁的破裂。lytN表型可以通过控制lytN的表达而逆转，但不能通过向葡萄球菌培养物中加入纯化的LytN来逆转。LytN含有LysM和LysM结构域，后者同时作为N-乙酰胞壁酰-L-丙氨酸酰胺酶和D-丙氨酰-甘氨酸内肽酶发挥功能。因此，LytN分泌到跨壁促进肽聚糖分离和葡萄球菌细胞周期的完成。
Cell cycle progression for the spherical microbe Staphylococcus aureus requires the coordinated synthesis and remodeling of peptidoglycan. The majority of these rearrangements takes place at the mid-cell, in a compartment designated the cross-wall. Secreted polypeptides endowed with a YSIRK-G/S signal peptide are directly delivered to the cross-wall compartment. One such YSIRK-containing protein is the murein hydrolase LytN. lytN mutations precipitate structural damage to the cross-wall and interfere with staphylococcal growth. Overexpression of lytN also affects growth and triggers rupture of the cross-wall. The lytN phenotype can be reversed by the controlled expression of lytN but not by adding purified LytN to staphylococcal cultures. LytN harbors LysM and CHAP domains, the latter of which functions as both an N-acetylmuramoyl-L-alanine amidase and D-alanyl-glycine endopeptidase. Thus, LytN secretion into the cross-wall promotes peptidoglycan separation and completion of the staphylococcal cell cycle.