Download MendeleyRotary mechanism of the prokaryotic V o motor driven by proton motive force.
Kishikawa, J.I., Nishida, Y., Nakano, A., Kato, T., Mitsuoka, K., Okazaki, K.I., Yokoyama, K.(2024) Nat Commun 15: 9883-9883
- PubMed: 39567487
- DOI: https://doi.org/10.1038/s41467-024-53504-x
- Primary Citation of Related Structures:
8YWT, 8YXZ, 8YY0, 8YY1 - PubMed Abstract:
ATP synthases play a crucial role in energy production by utilizing the proton motive force (pmf) across the membrane to rotate their membrane-embedded rotor c-ring, and thus driving ATP synthesis in the hydrophilic catalytic hexamer. However, the mechanism of how pmf converts into c-ring rotation remains unclear. This study presents a 2.8 Å cryo-EM structure of the V o domain of V/A-ATPase from Thermus thermophilus, revealing precise orientations of glutamate (Glu) residues in the c 12 -ring. Three Glu residues face a water channel, with one forming a salt bridge with the Arginine in the stator (a/Arg). Molecular dynamics (MD) simulations show that protonation of specific Glu residues triggers unidirectional Brownian motion of the c 12 -ring towards ATP synthesis. When the key Glu remains unprotonated, the salt bridge persists, blocking rotation. These findings suggest that asymmetry in the protonation of c/Glu residues biases c 12 -ring movement, facilitating rotation and ATP synthesis.
Organizational Affiliation:
Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto, 603-8555, Japan.
