Japan Agency for Medical Research and Development (AMED)
JP17am0101001
日本
引用
ジャーナル: Nat Commun / 年: 2024 タイトル: Rotary mechanism of the prokaryotic V motor driven by proton motive force. 著者: Jun-Ichi Kishikawa / Yui Nishida / Atsuki Nakano / Takayuki Kato / Kaoru Mitsuoka / Kei-Ichi Okazaki / Ken Yokoyama / 要旨: 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 ...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 domain of V/A-ATPase from Thermus thermophilus, revealing precise orientations of glutamate (Glu) residues in the c-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-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-ring movement, facilitating rotation and ATP synthesis.