Structural studies of the O-antigens of Yersinia pseudotuberculosis O:2a and mutants thereof with impaired 6-deoxy-D-manno-heptose biosynthesis pathway

The full structure of the long- and short-chain O-antigen of Yersinia pseudo tuberculosis O:2a containing two uncommon deoxy sugars, abequose and 6-deoxy-D-manno-heptose (6dmanHep), was established, for the first time, by sugar analysis, NMR spectroscopy, and high-resolution ESIMS. Similar structural studies were also performed on two 0:2a mutants with single disruption of 6dmanHep synthesis pathway genes each, which synthesize modified long-chain (dmhA mutant) and short-chain (both dmhA and dmhB mutants) O-antigens with 6dmanHep replaced by its putative biosynthetic precursor, D-glycero-D-manno-heptose. (C) 2008 Elsevier Ltd. All rights reserved.