Structure and genetics of biosynthesis of the glycosyl phosphate-containing O-polysaccharide of Escherichia coli O160

• Chemical structure of the O160 polysaccharide was established.
• The O-unit carries an acid-labile glycosyl phosphate linkages in the main chain.
• The O-antigen gene cluster includes six genes and is located between galF and gnd.

On mild acid degradation of the lipopolysaccharide of Escherichia coli O160, the O-polysaccharide was cleaved by acid-labile glycosyl phosphate linkages in the main chain. The resultant oligosaccharide and the alkali-treated lipopolysaccharide were studied by sugar analysis along with 1H and 13C NMR spectroscopies, and the following structure of the branched pentasaccharide repeating unit of the O-polysaccharide was established:Figure optionsDownload as PowerPoint slideThe O-antigen gene cluster of E. coli O160 was found to be consistent with the O-polysaccharide structure established.

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