5bw9
Crystal Structure of Yeast V1-ATPase in the Autoinhibited Form
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 ATPases (V-ATPases) are essential proton pumps that acidify the lumen of subcellular organelles in all eukaryotic cells and the extracellular space in some tissues. V-ATPase activity is regulated by a unique mechanism referred to as reversible disassembly, wherein the soluble catalytic sector, V1, is released from the membrane and its MgATPase activity silenced. The crystal structure of yeast V1 presented here shows that activity silencing involves a large conformational change of subunit H, with its C-terminal domain rotating ~150 degrees from a position near the membrane in holo V-ATPase to a position at the bottom of V1 near an open catalytic site. Together with biochemical data, the structure supports a mechanistic model wherein subunit H inhibits ATPase activity by stabilizing an open catalytic site that results in tight binding of inhibitory ADP at another site. Crystal structure of yeast V1-ATPase in the autoinhibited state.,Oot RA, Kane PM, Berry EA, Wilkens S EMBO J. 2016 Jun 13. pii: e201593447. PMID:27295975[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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