title: Characterization of E. coli O24 and O56 O antigen gene clusters reveals a complex evolutionary history of the O24 gene cluster.
abstract: O antigen is part of the lipopolysaccharide present in the outer membrane of Gram-negative bacteria. It has many different forms, which are almost entirely due to genetic variations of O antigen gene clusters. In this study, the O antigen gene clusters of E. coli O24 and O56 were sequenced, and all genes were assigned functions on the basis of homology. Comparison of O antigen gene clusters indicated that E. coli O24 O antigen gene cluster has possibly arisen from the E. coli O56 gene cluster, through inactivation of two glycosyltransferase genes and acquisition of two new genes from E. coli O157 and O152, respectively. The insertion sequence elements seemed to play important roles for the assembly of the O24 O antigen gene cluster. This is the first time that the evolutionary history of a multi-origin O antigen gene cluster is clearly demonstrated. Genes specific to E. coli O24 and O56 were also identified, which may be used for development of DNA-based serotyping schemes.
authors.affiliation: TEDA School of Biological Sciences and Biotechnology, Nankai University, 23 HongDa Street, Tianjin, TEDA, 300457, P.R. China.
authors.forename: Jiansong
authors.initials: J
authors.lastname: Cheng
authors.forename: Quan
authors.initials: Q
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Lu
authors.initials: L
authors.lastname: Feng
mesh_terms: D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000276:immunology; D019453:Escherichia coli O157 / Q000235:genetics* / Q000276:immunology; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D016695:Glycosyltransferases / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D019081:O Antigens / Q000737:chemistry / Q000235:genetics*; D016366:Open Reading Frames; D012703:Serotyping; D013045:Species Specificity
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D019081:O Antigens; D016695:Glycosyltransferases