3WPW

Structure of PomBc5, a periplasmic fragment of PomB from Vibrio

Summary for 3WPW

• Entry DOI: 10.2210/pdb3wpw/pdb
• Related: 3wpx
• Descriptor: PomB, ACETATE ION (3 entities in total)
• Functional Keywords: ompa-like, stator, peptidoglycan, membrane protein
• Biological source: Vibrio alginolyticus
• Total number of polymer chains: 2
• Total formula weight: 43091.27

Authors

Takao, M.,Sakuma, M.,Zhu, S.,Homma, M.,Kojima, S.,Imada, K. (deposition date: 2014-01-17, release date: 2014-09-10, Last modification date: 2024-03-20)

Primary citation

Zhu, S.,Takao, M.,Li, N.,Sakuma, M.,Nishino, Y.,Homma, M.,Kojima, S.,Imada, K.
Conformational change in the periplasmic region of the flagellar stator coupled with the assembly around the rotor
Proc. Natl. Acad. Sci. U.S.A., 111:13523-13528, 2014

PubMed Abstract: The torque of the bacterial flagellum is generated by the rotor-stator interaction coupled with the ion flow through the channel in the stator. Anchoring the stator unit to the peptidoglycan layer with proper orientation around the rotor is believed to be essential for smooth rotation of the flagellar motor. The stator unit of the sodium-driven flagellar motor of Vibrio is composed of PomA and PomB, and is thought to be fixed to the peptidoglycan layer and the T-ring by the C-terminal periplasmic region of PomB. Here, we report the crystal structure of a C-terminal fragment of PomB (PomBC) at 2.0-Å resolution, and the structure suggests a conformational change in the N-terminal region of PomBC for anchoring the stator. On the basis of the structure, we designed double-Cys replaced mutants of PomB for in vivo disulfide cross-linking experiments and examined their motility. The motility can be controlled reproducibly by reducing reagent. The results of these experiments suggest that the N-terminal disordered region (121-153) and following the N-terminal two-thirds of α1(154-164) in PomBC changes its conformation to form a functional stator around the rotor. The cross-linking did not affect the localization of the stator nor the ion conductivity, suggesting that the conformational change occurs in the final step of the stator assembly around the rotor.

PubMed: 25197056
DOI: 10.1073/pnas.1324201111

Experimental method

X-RAY DIFFRACTION (2 Å)