Download MendeleyStructural basis for assembly and function of the Salmonella flagellar MS-ring with three different symmetries.
Kinoshita, M., Makino, F., Miyata, T., Imada, K., Namba, K., Minamino, T.(2025) Commun Biol 8: 61-61
- PubMed: 39820129
- DOI: https://doi.org/10.1038/s42003-025-07485-2
- Primary Citation of Related Structures:
8ZDS, 8ZDT, 8ZDU - PubMed Abstract:
The flagellar MS-ring is the initial template for flagellar assembly and houses the flagellar protein export complex. The MS-ring has three parts of different symmetries within the ring structure by assembly of FliF subunits in two different conformations with distinct arrangements of three ring-building motifs, RBM1, RBM2, and RBM3. However, it remains unknown how these symmetries are generated. A combination of cryoEM structure and structure-based mutational analyses demonstrates that the well-conserved DQxGxxL motif in the RBM2-RBM3 hinge loop allows RBM2 to take two different orientations relative to RBM3. Of 34 FliF subunits of the MS-ring in the basal body, 23 RBM2 domains form an inner ring with a central pore that accommodates the flagellar protein export complex, and the remaining 11 RBM2 domains form 11 cog-like structures together with RBM1 domains just outside the inner RBM2-ring. We propose that a dimer of FliF with two different conformations initiates MS-ring assembly.
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
Organizational Affiliation:
