1hr9

Yeast Mitochondrial Processing Peptidase beta-E73Q Mutant Complexed with Malate Dehydrogenase Signal Peptide

spinqualitylabelsall models 1hr9, resolution 3.01Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1hr9 is a 12 chain structure with sequence from Saccharomyces cerevisiae and Saccharomyces cerevisiae S288C. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3.01Å Ligands: EPE, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MPPA_YEAST Cleaves presequences (transit peptides) from mitochondrial protein precursors. The cleavage sites typically contain an arginine at position -2 (in the N-terminal portion) from the scissible peptide bond in addition to other distal basic residues, and an aromatic residue at position +1. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: Mitochondrial processing peptidase (MPP) is a metalloendopeptidase that cleaves the N-terminal signal sequences of nuclear-encoded proteins targeted for transport from the cytosol to the mitochondria. Mitochondrial signal sequences vary in length and sequence, but each is cleaved at a single specific site by MPP. The cleavage sites typically contain an arginine at position -2 (in the N-terminal portion) from the scissile peptide bond in addition to other distal basic residues, and an aromatic residue at position +1. Mitochondrial import machinery recognizes amphiphilic helical conformations in signal sequences. However, it is unclear how MPP specifically recognizes diverse presequence substrates. RESULTS: The crystal structures of recombinant yeast MPP and a cleavage-deficient mutant of MPP complexed with synthetic signal peptides have been determined. MPP is a heterodimer; its alpha and beta subunits are homologous to the core II and core I proteins, respectively, of the ubiquinol-cytochrome c oxidoreductase complex. Crystal structures of two different synthetic substrate peptides cocrystallized with the mutant MPP each show the peptide bound in an extended conformation at the active site. Recognition sites for the arginine at position -2 and the +1 aromatic residue are observed. CONCLUSIONS: MPP bound two mitochondrial import presequence peptides in extended conformations in a large polar cavity. The presequence conformations differ from the amphiphilic helical conformation recognized by mitochondrial import components. Our findings suggest that the presequences adopt context-dependent conformations through mitochondrial import and processing, helical for recognition by mitochondrial import machinery and extended for cleavage by the main processing component. Crystal structures of mitochondrial processing peptidase reveal the mode for specific cleavage of import signal sequences.,Taylor AB, Smith BS, Kitada S, Kojima K, Miyaura H, Otwinowski Z, Ito A, Deisenhofer J Structure. 2001 Jul 3;9(7):615-25. PMID:11470436 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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