Crystal structures of the ATP-binding and ADP-release dwells of the V<sub>1</sub> rotary motor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27807367.
- Also identified by DOI 10.1038/ncomms13235 and PMC identifier 5095293.
- 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<sub>1</sub>-ATPases are highly conserved ATP-driven rotary molecular motors found in various membrane systems. We recently reported the crystal structures for the Enterococcus hirae A<sub>3</sub>B<sub>3</sub>DF (V<sub>1</sub>) complex, corresponding to the catalytic dwell state waiting for ATP hydrolysis. Here we present the crystal structures for two other dwell states obtained by soaking nucleotide-free V<sub>1</sub> crystals in ADP. In the presence of 20 μM ADP, two ADP molecules bind to two of three binding sites and cooperatively induce conformational changes of the third site to an ATP-binding mode, corresponding to the ATP-binding dwell. In the presence of 2 mM ADP, all nucleotide-binding sites are occupied by ADP to induce conformational changes corresponding to the ADP-release dwell. Based on these and previous findings, we propose a V<sub>1</sub>-ATPase rotational mechanism model.
Medical subject headings
- Vacuolar Proton-Translocating ATPases