1m60 | pdb_00001m60
Solution Structure of Zinc-substituted cytochrome c
Structural highlights
FunctionCYC_HORSE Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Plays a role in apoptosis. Suppression of the anti-apoptotic members or activation of the pro-apoptotic members of the Bcl-2 family leads to altered mitochondrial membrane permeability resulting in release of cytochrome c into the cytosol. Binding of cytochrome c to Apaf-1 triggers the activation of caspase-9, which then accelerates apoptosis by activating other caspases (By similarity). 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 PubMedZinc-substituted cytochrome c has been widely used in studies of protein-protein interactions and photo-induced electron transfer reactions between proteins. However, the coordination geometry of zinc in zinc-substituted cyt c has not yet been determined; two different opinions about the coordination have been reached. Here the solution structures of zinc-substituted cytochrome c that might be five-coordinated and six-coordinated have been refined separately by using (1)H NMR spectroscopy, and the zinc coordination geometry was determined just by NOE distance constraints. Structural analysis of the energy-minimized average solution structures of both the pentacoordinated and hexacoordinated geometries indicate that that zinc in zinc-substituted cyt c should be bound to both His18 and Met80, which means that the zinc is six-coordinated. RMSD values of the family of 25 six-coordinated structures from the average structure are 0.66+/-0.13 A and 1.09+/-0.16 A for the backbone and all heavy atoms, respectively. A statistical analysis of the structure indicates its satisfactory quality. Comparison of the solution structure of the six-coordinated energy-minimized average structure of zinc-substituted cytochrome c with the solution structure of reduced cytochrome c reveals that for the overall folding the secondary structure elements are very close. The availability of the structure provides for a better understanding of the protein-protein complex and for electron transfer processes between Zn cyt c and other metalloproteins. Structural analysis of zinc-substituted cytochrome c.,Qian C, Yao Y, Tong Y, Wang J, Tang W J Biol Inorg Chem. 2003 Apr;8(4):394-400. Epub 2002 Dec 14. PMID:12761660[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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