FliH and FliI ensure efficient energy coupling of flagellar type III protein export in Salmonella
| Autor: | Noritaka Hara, Satomi Koya, Tohru Minamino, Miki Kinoshita, Kunio Ihara, Yumi Inoue, Yusuke V. Morimoto, Keiichi Namba, Seiji Kojima, Michio Homma, Noriko Nishioka |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
cross‐complementation 030106 microbiology Mutant Sigma Factor Flagellum Microbiology 03 medical and health sciences Bacterial Proteins Salmonella Sigma factor Gene expression Original Research Vibrio Type III protein export Base Sequence biology mutational robustness Sequence Analysis DNA biology.organism_classification Transmembrane protein Cell biology Transport protein Bacterial flagella Protein Transport Proton-Translocating ATPases 030104 developmental biology Biochemistry Flagella Cytoplasm FlhA Genome Bacterial |
| Zdroj: | MicrobiologyOpen |
| ISSN: | 2045-8827 |
| DOI: | 10.1002/mbo3.340 |
| Popis: | For construction of the bacterial flagellum, flagellar proteins are exported via its specific export apparatus from the cytoplasm to the distal end of the growing flagellar structure. The flagellar export apparatus consists of a transmembrane (TM) export gate complex and a cytoplasmic ATPase complex consisting of FliH, FliI, and FliJ. FlhA is a TM export gate protein and plays important roles in energy coupling of protein translocation. However, the energy coupling mechanism remains unknown. Here, we performed a cross‐complementation assay to measure robustness of the energy transduction system of the export apparatus against genetic perturbations. Vibrio FlhA restored motility of a Salmonella ΔflhA mutant but not that of a ΔfliH‐fliI flhB(P28T) ΔflhA mutant. The flgM mutations significantly increased flagellar gene expression levels, allowing Vibrio FlhA to exert its export activity in the ΔfliH‐fliI flhB(P28T) ΔflhA mutant. Pull‐down assays revealed that the binding affinities of Vibrio FlhA for FliJ and the FlgN–FlgK chaperone–substrate complex were much lower than those of Salmonella FlhA. These suggest that Vibrio FlhA requires the support of FliH and FliI to efficiently and properly interact with FliJ and the FlgN–FlgK complex. We propose that FliH and FliI ensure robust and efficient energy coupling of protein export during flagellar assembly. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text