6xmu
From Proteopedia
Structure of P5A-ATPase Spf1, endogenous substrate-bound
Structural highlights
FunctionSPF1_YEAST Endoplasmic reticulum translocase required to remove mitochondrial transmembrane proteins mistargeted to the endoplasmic reticulum (PubMed:22918956, PubMed:32973005). Acts as a dislocase that mediates the ATP-dependent extraction of mislocalized mitochondrial transmembrane proteins from the endoplasmic reticulum membrane (PubMed:32973005). Specifically binds mitochondrial tail-anchored transmembrane proteins: has an atypically large substrate-binding pocket that recognizes and binds moderately hydrophobic transmembranes with short hydrophilic lumenal domains (PubMed:32973005).[1] [2] Publication Abstract from PubMedOrganelle identity depends on protein composition. How mistargeted proteins are selectively recognized and removed from organelles is incompletely understood. Here, we found that the orphan P5A-adenosine triphosphatase (ATPase) transporter ATP13A1 (Spf1 in yeast) directly interacted with the transmembrane segment (TM) of mitochondrial tail-anchored proteins. P5A-ATPase activity mediated the extraction of mistargeted proteins from the endoplasmic reticulum (ER). Cryo-electron microscopy structures of Saccharomyces cerevisiae Spf1 revealed a large, membrane-accessible substrate-binding pocket that alternately faced the ER lumen and cytosol and an endogenous substrate resembling an alpha-helical TM. Our results indicate that the P5A-ATPase could dislocate misinserted hydrophobic helices flanked by short basic segments from the ER. TM dislocation by the P5A-ATPase establishes an additional class of P-type ATPase substrates and may correct mistakes in protein targeting or topogenesis. The endoplasmic reticulum P5A-ATPase is a transmembrane helix dislocase.,McKenna MJ, Sim SI, Ordureau A, Wei L, Harper JW, Shao S, Park E Science. 2020 Sep 25;369(6511). pii: 369/6511/eabc5809. doi:, 10.1126/science.abc5809. PMID:32973005[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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