The outer core region of Helicobacter pylori lipopolysaccharide of the majority of isolates contains an alpha-1,6-glucan polymer synthesized by the product of the HP0159 ORF. Structural studies carried out on HP0159 lipopolysaccharide mutants by a combination of chemical methods, mass spectrometry and nuclear magnetic resonance spectroscopy confirmed that insertional inactivation of HP0159 gene in H. pylori strains 26695 and SS1 resulted in formation of a truncated lipopolysaccharide molecule characterized by the presence of a terminal dd-heptose residue in the side-chain outer core fragment and maintaining an inner core backbone structure compared with the wild-type Lewis antigen-expressing strains. Colonization studies with HP0159 mutants of two mouse-colonizing strains, SS1 and M6, confirmed their inability to successfully colonize the murine stomach.
Animals Bacterial Proteins