TY - JOUR
T1 - Characterization of the Escherichia coli O59 and O155 O-antigen gene clusters
T2 - The atypical wzx genes are evolutionary related
AU - Guo, Hongjie
AU - Kong, Qingke
AU - Cheng, Jiansong
AU - Wang, Lei
AU - Feng, Lu
N1 - Funding Information:
This work was supported by the Chinese National Science Fund for Distinguished Young Scholars (30125001), NSFC General Program (30270029, 30370339, 30370023), the 863 Program (2002AA2Z2051) and funding from the Science and Technology Committee of Tianjin City (013181711) to LW.
PY - 2005/7/15
Y1 - 2005/7/15
N2 - O-antigens are highly polymorphic. The genes specifically involved in O-antigen synthesis are generally grouped together on the chromosome as a gene cluster. In Escherichia coli, the O-antigen gene clusters are characteristically located between the housekeeping genes galF and gnd. In this study, the O-antigen gene clusters of E. coli O59 and E. coli O155 were sequenced. The former was found to contain genes for GDP-mannose synthesis, glycosyltransferase genes and the O-antigen polymerase gene (wzy), while the latter contained only glycosyltransferase genes and wzy. O unit flippase genes (wzx) were found immediately downstream of the gnd gene, in the region between the gnd and hisI genes in these two strains. This atypical location of wzx has not been reported before, and furthermore these two genes complemented in trans despite the fact that different O-antigen structures are present in E. coli O59 and O155. A putative acetyltransferase gene was found downstream of wzx in both strains. Comparison of the region between gnd and hisI revealed that the wzx and acetyltransferase genes are closely related between E. coli O59 and O155, indicating that the two gene clusters arose recently from a common ancestor. This work provides further evidence for the O-antigen gene cluster having formed gradually, and selection pressure will eventually bring O-antigen genes into a single cluster. Genes specific for E. coli O59 and O155, respectively, were also identified.
AB - O-antigens are highly polymorphic. The genes specifically involved in O-antigen synthesis are generally grouped together on the chromosome as a gene cluster. In Escherichia coli, the O-antigen gene clusters are characteristically located between the housekeeping genes galF and gnd. In this study, the O-antigen gene clusters of E. coli O59 and E. coli O155 were sequenced. The former was found to contain genes for GDP-mannose synthesis, glycosyltransferase genes and the O-antigen polymerase gene (wzy), while the latter contained only glycosyltransferase genes and wzy. O unit flippase genes (wzx) were found immediately downstream of the gnd gene, in the region between the gnd and hisI genes in these two strains. This atypical location of wzx has not been reported before, and furthermore these two genes complemented in trans despite the fact that different O-antigen structures are present in E. coli O59 and O155. A putative acetyltransferase gene was found downstream of wzx in both strains. Comparison of the region between gnd and hisI revealed that the wzx and acetyltransferase genes are closely related between E. coli O59 and O155, indicating that the two gene clusters arose recently from a common ancestor. This work provides further evidence for the O-antigen gene cluster having formed gradually, and selection pressure will eventually bring O-antigen genes into a single cluster. Genes specific for E. coli O59 and O155, respectively, were also identified.
KW - Escherichia coli serotypes O59 and O155
KW - O-antigen flippase
KW - Specific genes
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U2 - 10.1016/j.femsle.2005.05.036
DO - 10.1016/j.femsle.2005.05.036
M3 - Article
C2 - 15990253
AN - SCOPUS:21744453456
SN - 0378-1097
VL - 248
SP - 153
EP - 161
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
IS - 2
ER -