4ytw | pdb_00004ytw

Crystal structure of Ups1-Mdm35 complex

spinqualitylabelsall models 4ytw, resolution 1.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4ytw is a 4 chain structure with sequence from Baker's yeast. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 4ytv, 4ytx Gene: MDM35, YKL053C-A (Baker's yeast), UPS1, YLR193C (Baker's yeast) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [MDM35_YEAST] Involved in mitochondrial distribution and morphology. Mediates the import of UPS1, UPS2 and UPS3, 3 atypical mitochondrial intermembrane space (IMS) proteins lacking the two major IMS-targeting signals, into the intermembrane space. [UPS1_YEAST] Required for maintenance of normal mitochondrial morphology as well as PCP1-dependent processing of MGM1. With UPS2, controls the level of cardiolipin in mitochondria. Cardiolipin is a unique phospholipid with four fatty acid chains and is present mainly in the mitochondrial inner membrane where it stabilizes the electron transport chain supercomplex between complexes III and IV through direct interaction of their subunits. Publication Abstract from PubMed Eukaryotic cells are compartmentalized into membrane-bounded organelles whose functions rely on lipid trafficking to achieve membrane-specific compositions of lipids. Here we focused on the Ups1-Mdm35 system, which mediates phosphatidic acid (PA) transfer between the outer and inner mitochondrial membranes, and determined the X-ray structures of Mdm35 and Ups1-Mdm35 with and without PA. The Ups1-Mdm35 complex constitutes a single domain that has a deep pocket and flexible Omega-loop lid. Structure-based mutational analyses revealed that a basic residue at the pocket bottom and the Omega-loop lid are important for PA extraction from the membrane following Ups1 binding. Ups1 binding to the membrane is enhanced by the dissociation of Mdm35. We also show that basic residues around the pocket entrance are important for Ups1 binding to the membrane and PA extraction. These results provide a structural basis for understanding the mechanism of PA transfer between mitochondrial membranes. Structural and mechanistic insights into phospholipid transfer by Ups1-Mdm35 in mitochondria.,Watanabe Y, Tamura Y, Kawano S, Endo T Nat Commun. 2015 Aug 3;6:7922. doi: 10.1038/ncomms8922. PMID:26235513 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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