Abstract
Helicobacter pylori is a Gram-negative bacterium and human pathogen that is linked to various gastric diseases, including peptic ulcer disease, chronic gastritis, and gastric cancer. The filament of the H. pylori flagellum is surrounded by a membranous sheath that is contiguous with the outer membrane. Proteomic analysis of isolated sheathed flagella from H. pylori B128 identified the lipoprotein HP0135 as a potential component of the flagellar sheath. HP0135 is a small protein, with the mature HP0135 lipoprotein only 28 amino acid residues in length. Deletion of hp0135 in H. pylori B128 resulted in morphological abnormalities that included extensive formation of outer membrane vesicles and increased frequency of mini-cells. Introducing a plasmid-borne copy of hp0135 into the H. pylori Δhp0135 mutant suppressed the morphological abnormalities. The phenotype of the Δhp0135 mutant suggests HP0135 has roles in stabilizing the cell envelope and cell division.