Structure and gene cluster of the O-antigen of Escherichia coli O41

The acidic O-polysaccharide (O-antigen) of Escherichia coli O41 was studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy, and the following structure of the branched hexasaccharide repeating unit was established: This structure is unique among the known structures of bacterial polysaccharides. The O-antigen gene cluster of E. coli O41 was sequenced. The gene functions were tentatively assigned by a comparison with sequences in the available databases and found to be in full agreement with the E. coli O41 O-polysaccharide structure.