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Characterization of the Campylobacter jejuni heptosyltransferase II gene, waaF, provides genetic evidence that extracellular polysaccharide is lipid A core independent.

Abstract：

:Campylobacter jejuni produces both lipooligosaccharide (LOS) and a higher-molecular-weight polysaccharide that is believed to form a capsule. The role of these surface polysaccharides in C. jejuni-mediated enteric disease is unclear; however, epitopes associated with the LOS are linked to the development of neurological complications. In Escherichia coli and Salmonella enterica serovar Typhimurium the waaF gene encodes a heptosyltransferase, which catalyzes the transfer of the second L-glycero-D-manno-heptose residue to the core oligosaccharide moiety of lipopolysaccharide (LPS), and mutation of waaF results in a truncated core oligosaccharide. In this report we confirm experimentally that C. jejuni gene Cj1148 encodes the heptosyltransferase II enzyme, WaaF. The Campylobacter waaF gene complements an S. enterica serovar Typhimurium waaF mutation and restores the ability to produce full-sized lipopolysaccharide. To examine the role of WaaF in C. jejuni, waaF mutants were constructed in strains NCTC 11168 and NCTC 11828. Loss of heptosyltransferase activity resulted in the production of a truncated core oligosaccharide, failure to bind specific ligands, and loss of serum reactive GM(1), asialo-GM(1), and GM(2) ganglioside epitopes. The mutation of waaF did not affect the higher-molecular-weight polysaccharide supporting the production of a LOS-independent capsular polysaccharide by C. jejuni. The exact structural basis for the truncation of the core oligosaccharide was verified by comparative chemical analysis. The NCTC 11168 core oligosaccharide differs from that known for HS:2 strain CCUG 10936 in possessing an extra terminal disaccharide of galactose-beta(1,3) N-acetylgalactosamine. In comparison, the waaF mutant possessed a truncated molecule consistent with that observed with waaF mutants in other bacterial species.

journal_name

J Bacteriol

journal_title

Journal of bacteriology

authors

Oldfield NJ,Moran AP,Millar LA,Prendergast MM,Ketley JM

doi

10.1128/jb.184.8.2100-2107.2002

keywords:

subject

Has Abstract

pub_date

2002-04-01 00:00:00

pages

2100-7

issue

eissn

0021-9193

issn

1098-5530

journal_volume

184

pub_type

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Characterization of the Campylobacter jejuni heptosyltransferase II gene, waaF, provides genetic evidence that extracellular polysaccharide is lipid A core independent.