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bioRxiv · 10.1101/2021.11.09.467972

Coordinated conformational changes in the V1 complex during V-ATPase reversible dissociation

Vasanthakumar, T.·Keon, K. A.·Bueler, S. A.·Jaskolka, M. C.·Rubinstein, J. L.
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Abstract

Vacuolar-type ATPases (V-ATPases) are rotary enzymes that acidify intracellular compartments in eukaryotic cells. These multi-subunit complexes consist of a cytoplasmic V1 region that hydrolyzes ATP and a membrane-embedded VO region that transports protons. V-ATPase activity is regulated by reversible dissociation of the two regions, with the isolated V1 and VO complexes becoming autoinhibited upon disassembly and subunit C subsequently detaching from V1. In yeast, assembly of the V1 and VO regions is mediated by the RAVE complex through an unknown mechanism. We used cryoEM of yeast V-ATPase to determine structures of the intact enzyme, the dissociated but complete V1 complex, and the V1 complex lacking subunit C. Upon separation, V1 undergoes a dramatic conformational rearrangement, with its rotational state becoming incompatible for reassembly with VO. Loss of subunit C allows V1 to match the rotational state of VO, suggesting how RAVE could reassemble V1 and VO by recruiting subunit C.

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Vasanthakumar, T., Keon, K. A., Bueler, S. A., Jaskolka, M. C., Rubinstein, J. L.. 2021-11-09. Coordinated conformational changes in the V1 complex during V-ATPase reversible dissociation. https://doi.org/10.1101/2021.11.09.467972

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