Structure and gene cluster of the O-antigen of Enterobacter cloacae G3422

Abstract

The O-polysaccharide (OPS) was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae G3422 and studied by chemical methods, including sugar analyses, Smith degradation, and solvolysis with anhydrous trifluoroacetic acid, along with 1H and 13C NMR spectroscopy. The following structure of the branched tetrasaccharide repeating unit was established: [Display omitted] The O-antigen gene cluster of Enterobacter cloacae G3422 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in a good agreement with the O-antigen structure.