Peptidoglycan in obligate intracellular bacteria.
Peptidoglycan in obligate intracellular bacteria.
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DOI：
10.1111/mmi.13880
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发表时间：
2018-01
影响因子：
3.6
通讯作者：
Salje J
中科院分区：
文献类型：
--
作者：
Otten C;Brilli M;Vollmer W;Viollier PH;Salje J
肽聚糖是大多数细菌细胞包膜中的主要应力承载结构，也是真核免疫系统的有效刺激物。专性细胞内细菌只在活细胞内部复制，这是一个受保护的生态位。在这些条件下，不一定需要肽聚糖来维持细菌细胞的完整性。此外，肽聚糖的存在使细菌处于被宿主肽聚糖识别因子和下游效应物检测和破坏的风险中。这导致了选择性压力和降低肽聚糖水平的机会。在这篇综述中，我们分析了肽聚糖代谢的主要专性细胞内细菌物种的基因的发生。通过这种比较分析，我们确定了一组预测的“肽聚糖中间体”微生物，包括衣原体、恙虫病东方体、沃尔巴克氏体和边缘无浆体。这种分组可能反映了其感染周期与肽聚糖阴性专性胞内细菌（如埃里希体属和嗜吞噬细胞无形体属）以及具有经典肽聚糖的专性胞内细菌（如柯克斯体属、布赫内拉氏菌属和立克次体属成员）相比的生物学差异。肽聚糖中间体组的特征基因集揭示了构建肽聚糖样球囊和/或分裂隔膜的最低酶促要求。
Peptidoglycan is the predominant stress‐bearing structure in the cell envelope of most bacteria, and also a potent stimulator of the eukaryotic immune system. Obligate intracellular bacteria replicate exclusively within the interior of living cells, an osmotically protected niche. Under these conditions peptidoglycan is not necessarily needed to maintain the integrity of the bacterial cell. Moreover, the presence of peptidoglycan puts bacteria at risk of detection and destruction by host peptidoglycan recognition factors and downstream effectors. This has resulted in a selective pressure and opportunity to reduce the levels of peptidoglycan. In this review we have analysed the occurrence of genes involved in peptidoglycan metabolism across the major obligate intracellular bacterial species. From this comparative analysis, we have identified a group of predicted ‘peptidoglycan‐intermediate’ organisms that includes the Chlamydiae, Orientia tsutsugamushi, Wolbachia and Anaplasma marginale. This grouping is likely to reflect biological differences in their infection cycle compared with peptidoglycan‐negative obligate intracellular bacteria such as Ehrlichia and Anaplasma phagocytophilum, as well as obligate intracellular bacteria with classical peptidoglycan such as Coxiella, Buchnera and members of the Rickettsia genus. The signature gene set of the peptidoglycan‐intermediate group reveals insights into minimal enzymatic requirements for building a peptidoglycan‐like sacculus and/or division septum.