7tmq
From Proteopedia
V1 complex lacking subunit C from Saccharomyces cerevisiae, State 3
Structural highlights
FunctionVATA_YEAST Catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase (vacuolar ATPase) is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mV, inside positive and acidic, in the vacuolar membrane vesicles. It may participate in maintenance of cytoplasmic Ca(2+) homeostasis. This is a catalytic subunit.[1] PI-SceI is an endonuclease that can cleave at a site present in a VMA1 allele that lacks the derived endonuclease segment of the open reading frame; cleavage at this site only occurs during meiosis and initiates "homing", a genetic event that converts a VMA1 allele lacking VDE into one that contains it.[2] Publication Abstract from PubMedVacuolar-type ATPases (V-ATPases) are rotary enzymes that acidify intracellular compartments in eukaryotic cells. These multi-subunit complexes consist of a cytoplasmic V(1) region that hydrolyzes ATP and a membrane-embedded V(O) region that transports protons. V-ATPase activity is regulated by reversible dissociation of the two regions, with the isolated V(1) and V(O) complexes becoming autoinhibited on disassembly and subunit C subsequently detaching from V(1). In yeast, assembly of the V(1) and V(O) 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(1) complex and the V(1) complex lacking subunit C. On separation, V(1) undergoes a dramatic conformational rearrangement, with its rotational state becoming incompatible for reassembly with V(O). Loss of subunit C allows V(1) to match the rotational state of V(O), suggesting how RAVE could reassemble V(1) and V(O) by recruiting subunit C. Coordinated conformational changes in the V(1) complex during V-ATPase reversible dissociation.,Vasanthakumar T, Keon KA, Bueler SA, Jaskolka MC, Rubinstein JL Nat Struct Mol Biol. 2022 May;29(5):430-439. doi: 10.1038/s41594-022-00757-z. , Epub 2022 Apr 25. PMID:35469063[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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