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.d.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-19758 |
| Date | 23 August 2005 |
| Creators | Tran, An X., Stead, Christopher M., Trent, M. Stephen |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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