A Tripartite Efflux System Affects Flagellum Stability in Helicobacter pylori
Katherine Gibson1, Joshua K Chu1, Shiwei Zhu2,3
1Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
International Journal of Molecular Sciences
|October 14, 2022
Summary
Helicobacter pylori flagellum stability is linked to a tripartite efflux system (HP1486-HP1489). Mutations in this system reduce motility and flagella number, impacting bacterial swimming.
Area of Science:
- Microbiology
- Bacterial Motility
- Protein Function
Background:
- Helicobacter pylori utilizes flagella for motility.
- Flagellar structure varies among Helicobacter species, with some possessing sheathed flagella.
Purpose of the Study:
- To identify proteins involved in flagellar function and stability in H. pylori.
- To investigate the role of a novel tripartite efflux system in H. pylori flagellar assembly and motility.
Main Methods:
- Comparative genomic analysis to identify conserved and divergent proteins.
- Gene deletion mutagenesis to create H. pylori mutants (Δhp1486/hp1487, Δhp1489).
- Cryo-electron tomography to visualize flagellar motor structures in wild-type and mutant cells.
Main Results:
- Deletion of hp1486/hp1487 and hp1489 homologs reduced H. pylori motility and flagella number.
- Cryo-electron tomography revealed flagellum disassembly products and aberrant motor structures in mutants.
- Motile variants of the Δhp1486/hp1487 mutant exhibited frameshift mutations in fliL, suggesting FliL's role in disassembly.
Conclusions:
- The HP1486-HP1489 tripartite efflux system is crucial for H. pylori flagellum stability.
- FliL appears to play a role in flagellum disassembly during H. pylori motility regulation.
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