Japan Agency for Medical Research and Development (AMED)
JP19am0101117
日本
Japan Agency for Medical Research and Development (AMED)
JP21am0101117
日本
Japan Agency for Medical Research and Development (AMED)
JP17pc0101020
日本
Ministry of Education, Culture, Sports, Science and Technology (Japan)
JP20H05532
日本
Ministry of Education, Culture, Sports, Science and Technology (Japan)
JP22H04844
日本
引用
ジャーナル: Commun Biol / 年: 2025 タイトル: Structural basis for assembly and function of the Salmonella flagellar MS-ring with three different symmetries. 著者: Miki Kinoshita / Fumiaki Makino / Tomoko Miyata / Katsumi Imada / Keiichi Namba / Tohru Minamino / 要旨: 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 ...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.