3W1E

Structure of FlgT, a flagellar basal body component protein

Summary for 3W1E

• Entry DOI: 10.2210/pdb3w1e/pdb
• Descriptor: Flagella basal-body protein (2 entities in total)
• Functional Keywords: h-ring formation, the flagellar basal body, motor protein
• Biological source: Vibrio alginolyticus
• Total number of polymer chains: 1
• Total formula weight: 41105.62

Authors

Terashima, H.,Sakuma, M.,Homma, M.,Imada, K. (deposition date: 2012-11-14, release date: 2013-04-03, Last modification date: 2024-10-30)

Primary citation

Terashima, H.,Li, N.,Sakuma, M.,Koike, M.,Kojima, S.,Homma, M.,Imada, K.
Insight into the assembly mechanism in the supramolecular rings of the sodium-driven Vibrio flagellar motor from the structure of FlgT
Proc.Natl.Acad.Sci.USA, 110:6133-6138, 2013

PubMed Abstract: Flagellar motility is a key factor for bacterial survival and growth in fluctuating environments. The polar flagellum of a marine bacterium, Vibrio alginolyticus, is driven by sodium ion influx and rotates approximately six times faster than the proton-driven motor of Escherichia coli. The basal body of the sodium motor has two unique ring structures, the T ring and the H ring. These structures are essential for proper assembly of the stator unit into the basal body and to stabilize the motor. FlgT, which is a flagellar protein specific for Vibrio sp., is required to form and stabilize both ring structures. Here, we report the crystal structure of FlgT at 2.0-Å resolution. FlgT is composed of three domains, the N-terminal domain (FlgT-N), the middle domain (FlgT-M), and the C-terminal domain (FlgT-C). FlgT-M is similar to the N-terminal domain of TolB, and FlgT-C resembles the N-terminal domain of FliI and the α/β subunits of F1-ATPase. To elucidate the role of each domain, we prepared domain deletion mutants of FlgT and analyzed their effects on the basal-body ring formation. The results suggest that FlgT-N contributes to the construction of the H-ring structure, and FlgT-M mediates the T-ring association on the LP ring. FlgT-C is not essential but stabilizes the H-ring structure. On the basis of these results, we propose an assembly mechanism for the basal-body rings and the stator units of the sodium-driven flagellar motor.

PubMed: 23530206
DOI: 10.1073/pnas.1222655110

Experimental method

X-RAY DIFFRACTION (2 Å)