Psakis, Georgios, Saidijam, Massoud, Shibayama, Keigo, Polaczek, Julia, Bettaney, Kim E., Baldwin, Jocelyn M., Baldwin, Stephen A., Hope, Ryan, Essen, Lars-Oliver, Essenberg, Richard C. and Henderson, Peter J.F. (2008) The sodium-dependent D-glucose transport protein of Helicobacter pylori. Molecular microbiology, 71 (2). pp. 391-403. ISSN 1365-2958

Helicobacter pylori is a gram-negative pathogenic microaerophile with a particular tropism for the mucosal surface of the gastric epithelium. Despite its obligatory microaerophilic character, it can metabolize D-glucose and/or D-galactose in both oxidative and fermentative pathways via a Na(+)-dependent secondary active transport, a glucokinase and enzymes of the pentose phosphate pathway. We have assigned the Na(+)-dependent transport of glucose to the protein product of the H. pylori 1174 gene. The gene was heterologously expressed in a glucose transport-deficient Escherichia coli strain, where transport activities of radiolabelled D-glucose, D-galactose and 2-deoxy-D-glucose were restored, consistent with the expected specificity of the hexose uptake system in H. pylori. D-mannose was also identified as a substrate. The HP1174 transport protein was purified and reconstituted into proteoliposomes, where sodium dependence of sugar transport activity was demonstrated. Additionally the tryptophan/tyrosine fluorescence of the purified protein showed quenching by 2-deoxy-D-glucose, D-mannose, D-glucose or D-galactose in the presence of sodium ions. This is the first reported purification and characterization of an active glucose transport protein member of the TC 2.1.7 subgroup of the Major Facilitator Superfamily, constituting the route for entry of sugar nutrients into H. pylori. A model is derived of its three-dimensional structure as a paradigm of the family.

Mol_Micro_Psakis_Henderson_241008.pdf - Accepted Version

Download (579kB) | Preview
MolMicrob_suppl.pdf - Supplemental Material

Download (852kB) | Preview
Mol_Micro_Psakis_Henderson_241008.doc - Accepted Version
Restricted to Repository staff only

Download (392kB)


Downloads per month over past year

Downloads per month over past year for

Downloads per month over past year for

Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email