The variation of O antigens in gram-negative bacteria.
The O antigen, consisting of many repeats of an oligosaccharide unit, is part of the lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria. It is on the cell surface and appears to be a major target for both immune system and bacteriophages, and therefore becomes one of the most variable cell constituents. The variability of the O antigen provides the major basis for serotyping schemes of Gram-negative bacteria. The genes responsible for the synthesis of O antigen are usually in a single cluster known as O antigen gene cluster, and their location on the chromosome within a species is generally conserved. Three O antigen biosynthesis pathways including Wzx/Wzy, ABC-transporter and Synthase have been discovered. In this chapter, the traditional and molecular O serotyping schemes are compared, O antigen structures and gene clusters of well-studied species are described, processes for formation and distribution of the variety of O antigens are discussed, and finally, the role of O antigen in bacterial virulence.
Wang
Lei
L
TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin, 300457, China. wanglei@nankai.edu.cn
Wang
Quan
Q
Reeves
Peter R
PR
D001435:Bacteriophages / Q000235:genetics / Q000378:metabolism; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D022761:Gene Transfer, Horizontal; D006090:Gram-Negative Bacteria / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity; D006801:Humans; D008969:Molecular Sequence Data; D015394:Molecular Structure; D005810:Multigene Family; D019081:O Antigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D012703:Serotyping / Q000379:methods
D019081:O Antigens