Coordinated conformational changes in the V 1 complex during V-ATPase reversible dissociation

• Published in: Nature structural & molecular biology Vol. 29; no. 5; p. 430
• Main Authors: Vasanthakumar, Thamiya, Keon, Kristine A, Bueler, Stephanie A, Jaskolka, Michael C, Rubinstein, John L
• Format: Journal Article
• Language: English
• Published: United States 01.05.2022
• ISSN: 1545-9985

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