Mechanism of ATP hydrolysis dependent rotation of bacterial ATP synthase
説明
<jats:title>Abstract</jats:title><jats:p>F<jats:sub>1</jats:sub> domain of ATP synthase is a rotary ATPase complex in which rotation of central γ-subunit proceeds in 120° steps against a surrounding α<jats:sub>3</jats:sub>β<jats:sub>3</jats:sub> fueled by ATP hydrolysis. How the ATP hydrolysis reactions occurring in three catalytic αβ dimers are coupled to mechanical rotation is a key outstanding question. Here we describe catalytic intermediates of the F<jats:sub>1</jats:sub> domain in F<jats:sub>o</jats:sub>F<jats:sub>1</jats:sub> synthase from <jats:italic>Bacillus PS3</jats:italic> sp. during ATP mediated rotation captured using cryo-EM. The structures reveal that three catalytic events and the first 80° rotation occur simultaneously in F<jats:sub>1</jats:sub> domain when nucleotides are bound at all the three catalytic αβ dimers. The remaining 40° rotation of the complete 120° step is driven by completion of ATP hydrolysis at α<jats:sub>D</jats:sub>β<jats:sub>D</jats:sub>, and proceeds through three sub-steps (83°, 91°, 101°, and 120°) with three associated conformational intermediates. All sub-steps except for one between 91° and 101° associated with phosphate release, occur independently of the chemical cycle, suggesting that the 40° rotation is largely driven by release of intramolecular strain accumulated by the 80° rotation. Together with our previous results, these findings provide the molecular basis of ATP driven rotation of ATP synthases.</jats:p>
収録刊行物
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- Nature Communications
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Nature Communications 14 (1), 2023-07-10
Springer Science and Business Media LLC