O-antigen polysaccharide is a major immunogenic feature of the lipopolysaccharide of Gram-negative bacteria, and most species produce a large variety of forms that differ substantially from one another. There are 18 known O-antigen forms in the Yersinia pseudotuberculosis complex, which are typical in being composed of multiple copies of a short oligosaccharide called an O unit. The O-antigen gene clusters are located between the hemH and gsk genes, and are atypical as 15 of them are closely related, each having one of five downstream gene modules for alternative main-chain synthesis, and one of seven upstream modules for alternative side-branch sugar synthesis. As a result, many of the genes are in more than one gene cluster. The gene order in each module is such that, in general, the earlier a gene product functions in O-unit synthesis, the closer the gene is to the 5 end for side-branch modules or the 3 end for main-chain modules. We propose a model whereby natural selection could generate the observed pattern in gene order, a pattern that has also been observed in other species.
Lipopolysaccharide, serotype, O antigen, gene cluster, O-specific polysaccharide, Yersinia pseudotuberculosis, O-antigen polysaccharide
NCBI PubMed ID: 28364730Publication DOI: 10.1093/femsre/fux002Journal NLM ID: 8902526Publisher: Oxford University Press
Correspondence: peter.reeves@sydney.edu.au
Institutions: School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia, Institute of Health and Biomedical Innovation, Queensland University of Technology. Brisbane, QLD 4001, Australia
Methods: function analysis of gene clusters