Structural snapshots of V/A-ATPase reveal the rotary catalytic mechanism of rotary ATPases.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35260556.
- Also identified by DOI 10.1038/s41467-022-28832-5 and PMC identifier 8904598.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
V/A-ATPase is a motor protein that shares a common rotary catalytic mechanism with F<sub>o</sub>F<sub>1</sub> ATP synthase. When powered by ATP hydrolysis, the V<sub>1</sub> domain rotates the central rotor against the A<sub>3</sub>B<sub>3</sub> hexamer, composed of three catalytic AB dimers adopting different conformations (AB<sub>open</sub>, AB<sub>semi</sub>, and AB<sub>closed</sub>). Here, we report the atomic models of 18 catalytic intermediates of the V<sub>1</sub> domain of V/A-ATPase under different reaction conditions, determined by single particle cryo-EM. The models reveal that the rotor does not rotate immediately after binding of ATP to the V<sub>1</sub>. Instead, three events proceed simultaneously with the 120˚ rotation of the shaft: hydrolysis of ATP in AB<sub>semi</sub>, zipper movement in AB<sub>open</sub> by the binding ATP, and unzipper movement in AB<sub>closed</sub> with release of both ADP and Pi. This indicates the unidirectional rotation of V/A-ATPase by a ratchet-like mechanism owing to ATP hydrolysis in AB<sub>semi</sub>, rather than the power stroke model proposed previously for F<sub>1</sub>-ATPase.
Medical subject headings
- Adenosine Triphosphatases
- Adenosine Triphosphate