Vollmer Waldemar
Institute for Cell and Molecular Biosciences, Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
FEMS Microbiol Rev. 2008 Mar;32(2):287-306. doi: 10.1111/j.1574-6976.2007.00088.x. Epub 2007 Dec 5.
The normal, unmodified glycan strands of bacterial peptidoglycan consist of alternating residues of beta-1,4-linked N-acetylmuramic acid and N-acetylglucosamine. In many species the glycan strands become modified after their insertion into the cell wall. This review describes the structure of secondary modifications and of attachment sites of surface polymers in the glycan strands of peptidoglycan. It also provides an overview of the occurrence of these modifications in various bacterial species. Recently, enzymes responsible for the N-deacetylation, N-glycolylation and O-acetylation of the glycan strands were identified. The presence of these modifications affects the hydrolysis of peptidoglycan and its enlargement during cell growth. Glycan strands are frequently deacetylated and/or O-acetylated in pathogenic species. These alterations affect the recognition of bacteria by host factors, and contribute to the resistance of bacteria to host defence factors such as lysozyme.
细菌肽聚糖的正常、未修饰的聚糖链由β-1,4-连接的N-乙酰胞壁酸和N-乙酰葡糖胺的交替残基组成。在许多物种中，聚糖链在插入细胞壁后会发生修饰。本综述描述了肽聚糖聚糖链中二级修饰的结构以及表面聚合物的附着位点。它还概述了这些修饰在各种细菌物种中的发生情况。最近，负责聚糖链N-脱乙酰化、N-糖基化和O-乙酰化的酶被鉴定出来。这些修饰的存在会影响肽聚糖的水解及其在细胞生长过程中的扩展。在致病物种中，聚糖链经常发生脱乙酰化和/或O-乙酰化。这些改变会影响宿主因子对细菌的识别，并有助于细菌对诸如溶菌酶等宿主防御因子产生抗性。
