Identification and molecular characterization of a major ring-forming surface protein from the gastric pathogen...

Area of Science:

• Microbiology
• Bacterial cell surface structures
• Helicobacter research

Background:

• Helicobacter mustelae is associated with gastritis and gastric ulcers in ferrets.
• The cell surface of H. mustelae has not been extensively characterized.
• Understanding bacterial surface structures is crucial for pathogenesis and host interaction.

Purpose of the Study:

• To characterize the unique ring structures on the surface of Helicobacter mustelae.
• To identify and analyze the protein composing these rings.
• To investigate the genetic basis and distribution of this protein within Helicobacter species.

Main Methods:

• Electron microscopy to visualize cell surface structures.
• Protein purification and N-terminal sequencing.
• Antibody production and immunogold labeling for localization.
• Gene cloning, expression in E. coli, and nucleotide sequencing.

Main Results:

• A laterally extensive array of 8.5-nm-diameter rings composed of a 150kDa protein was identified on H. mustelae.
• The hsr gene encoding this protein was cloned and sequenced, revealing a mature protein of 152,300 Da.
• Cross-reactivity was observed in other H. mustelae strains but not in Helicobacter pylori or Helicobacter felis.

Conclusions:

• Helicobacter mustelae possesses a distinct cell surface characterized by a dense array of 8.5 nm protein rings.
• This protein and its gene (hsr) are specific to H. mustelae, differentiating it from other Helicobacter species.
• The findings provide insights into the unique surface architecture of H. mustelae and potential targets for diagnostics or therapeutics.