Structure and gene cluster of the O-antigen of Enterobacter cloacae C4115

Abstract

An O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Enterobacter cloacae C4115 and studied by sugar analysis along with 1D and 2D 1H and 13C NMR spectroscopy. The following structure of the linear pentasaccharide repeating unit of the O-polysaccharide was established:→2)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 2)-α-l-Rhap-(1 → 2)-α-d-Galp-(1 → 3)-α-d-FucpNAc-(1→The O-antigen gene cluster of E. cloacae C4115 was sequenced. The gene functions were tentatively assigned by comparison with sequences in the available databases and found to be in consistence with the O-polysaccharide structure. The O-antigen structure and gene cluster of E. cloacae C4115 are similar to those of E. cloacae G3421 studied by us earlier (Perepelov A.V. et al. Carbohydr. Res. 427 (2016) 55–59).