Publication Date:
2017-01-08
Description:
Helicobacter pylori is an important cause of gastric pathologies and persistent infection can lead to stomach cancer. Virulent H. pylori strains encode a type IV secretion system responsible for translocation of the oncogenic CagA protein into cells of the gastric mucosa. Gene HP0522 encodes the essential component Cag (Cag3), and we show by gel filtration and cross-linking that purified Cag forms high molecular mass complexes. In contrast, its interaction partner CagT is mostly monomeric, but co-fractionates after gel filtration. Analysis by transmission electron microscopy revealed that purified Cag complexes can self-assemble ring-like structures. Cag-overexpressing Escherichia coli exhibits membrane-associated circular profiles in regions of the cell envelope with intense immunogold labelling with a Cag-specific antiserum. Our results suggest that Cag has the capacity to form macromolecular structures contributing to the assembly of the type IV secretion system.
Keywords:
Pathogens & Pathogenicity
Print ISSN:
0378-1097
Electronic ISSN:
1574-6968
Topics:
Biology
