title: Remodeling of Helicobacter pylori lipopolysaccharide.
abstract: Modification of the lipid A domain of lipopolysaccharide (LPS) has been reported to contribute to the virulence and pathogenesis of various Gram-negative bacteria. The Kdo (3-deoxy-D-manno-octulosonic acid)-lipid A domain of Helicobacter pylori LPS shows several differences to that of Escherichia coli. It has fewer acyl chains, a reduced number of phosphate groups, much lower immunobiological activity, and only a single Kdo sugar is attached to the disaccharide backbone. However, H. pylori synthesizes a minor lipid A species resembling that of E. coli, which is both bis-phosphorylated and hexa-acylated suggesting that the major species results from the action of specific modifying enzymes. This work describes two enzymes, a lipid A phosphatase and a phosphoethanolamine transferase, involved in the periplasmic modification of the 1-position of H. pylori lipid A. Furthermore, we report a novel Kdo trimming enzyme that requires prior removal of the 1-phosphate group for enzymatic activity. Discovery of the enzymatic machinery involved in the remodeling of H. pylori LPS will help unravel the importance of these modifications in H. pylori pathogenesis.
authors.affiliation: Department of Microbiology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, USA.
authors.forename: An X
authors.initials: AX
authors.lastname: Tran
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Stead
authors.forename: M Stephen
authors.initials: MS
authors.lastname: Trent
mesh_terms: D004982:Ethanolaminephosphotransferase / Q000502:physiology; D016480:Helicobacter pylori; D008050:Lipid A / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000502:physiology
chemical_list: D008050:Lipid A; D004982:Ethanolaminephosphotransferase; D010744:Phosphoric Monoester Hydrolases