Structure and gene cluster of the O-antigen of Escherichia coli O68

• Structure of the O-polysaccharide of E. coli O68 was established.
• Solvolysis with trifluoroacetic acid was applied to selective cleavage of the rhamnosidic linkage.
• The O-antigen gene cluster of E. coli O68 has been sequenced.

The O-polysaccharide (O-antigen) of Escherichia coli O68 was studied by sugar analysis, partial solvolysis with anhydrous trifluoroacetic acid, and 1D and 2D 1H and 13C NMR spectroscopies. The following structure of the branched heptasaccharide repeating unit was established:Figure optionsDownload as PowerPoint slideThe O-antigen gene cluster of E. coli O68 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in full agreement with the O-antigen structure.

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