Structure of the O-antigen of Salmonella O66 and the genetic basis for similarity and differences between the closely related O-antigens of Escherichia coli O166 and Salmonella O66.
Structure of the O-antigen of Salmonella O66 and the genetic basis for similarity and differences between the closely related O-antigens of Escherichia coli O166 and Salmonella O66.
复制标题
沙门氏菌O66 O抗原的结构以及密切相关的大肠杆菌O166和沙门氏菌O66 O抗原相似性和差异性的遗传基础。
DOI：
10.1099/mic.0.037325-0
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发表时间：
2010
期刊：
影响因子：
1.5
通讯作者：
Lei Wang
中科院分区：
文献类型：
--
作者：
B. Liu;A. Perepelov;Dan Li;S. Senchenkova;Yanfang Han;A. Shashkov;Lu Feng;Y. Knirel;Lei Wang
O-抗原是革兰氏阴性细菌外膜的一种成分，也是细胞表面变化最大的成分之一，导致主要的抗原性变异。O-抗原构成了细菌血清分型的基础。本研究建立了沙门氏菌O66的O-抗原结构，它与已知的大肠杆菌O166的O-抗原结构只有一个连接(很可能是O-单位之间的连接)和O-乙酰化。沙门氏菌O66和大肠杆菌O166的O抗原基因簇具有相似的组织结构，唯一的例外是沙门氏菌O66的wzy基因被非编码区取代。通过缺失和反式互补突变体的构建和分析，证实了大肠杆菌O166中wzy基因的功能。正如以前在沙门氏菌A、B和D1群中所报道的那样，O66沙门氏菌O-抗原的生物合成涉及位于O-抗原基因簇之外的一个功能性wzy基因。O66沙门氏菌与O166沙门氏菌O抗原基因簇对应基因的序列同源性在~70%之间，提示它们可能起源于同一祖先。在物种分化后，O66沙门氏菌可能通过灭活位于O抗原基因簇中的wzy基因和获得两个位于O抗原基因簇之外的新基因(一个wzy基因和一个用于O-乙酰化修饰的原噬菌体基因)而获得其特有的O抗原形式。
O-antigen is a component of the outer membrane of Gram-negative bacteria and is one of the most variable cell surface constituents, leading to major antigenic variability. The O-antigen forms the basis for bacterial serotyping. In this study, the O-antigen structure of Salmonella O66 was established, which differs from the known O-antigen structure of Escherichia coli O166 only in one linkage (most likely the linkage between the O-units) and O-acetylation. The O-antigen gene clusters of Salmonella O66 and E. coli O166 were found to have similar organizations, the only exception being that in Salmonella O66, the wzy gene is replaced by a non-coding region. The function of the wzy gene in E. coli O166 was confirmed by the construction and analysis of deletion and trans-complementation mutants. It is proposed that a functional wzy gene located outside the O-antigen gene cluster is involved in Salmonella O66 O-antigen biosynthesis, as has been reported previously in Salmonella serogroups A, B and D1. The sequence identity for the corresponding genes between the O-antigen gene clusters of Salmonella O66 and E. coli O166 ranges from 64 to 70 %, indicating that they may originate from a common ancestor. It is likely that after the species divergence, Salmonella O66 got its specific O-antigen form by inactivation of the wzy gene located in the O-antigen gene cluster and acquisition of two new genes (a wzy gene and a prophage gene for O-acetyl modification) both residing outside the O-antigen gene cluster.