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CRYSTAL STRUCTURE OF COBALT(III)-SUBSTITUTED CYTOCHROME C (TUNA)CRYSTAL STRUCTURE OF COBALT(III)-SUBSTITUTED CYTOCHROME C (TUNA)
Structural highlights
FunctionCYC_THUAA 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. 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 PubMedReplacement of iron with cobalt(III) selectively introduces a deep trap in the folding-energy landscape of the heme protein cytochrome c. Remarkably, neither the protein structure nor the folding thermodynamics is perturbed by this metal-ion substitution, as shown by data from spectroscopic and x-ray diffraction experiments. Through kinetics measurements, we have found parallel folding pathways involving several different misligated Co(III) species, and, as these folding intermediates persist for several hours under certain conditions, we have been able to elucidate fully their spectroscopic properties. The results, along with an analysis of the fluorescence energy-transfer kinetics during refolding, show that rapidly equilibrating populations of compact and extended polypeptide conformations are present until all molecules have reached the native structure. These measurements provide direct evidence that collapsed denatured structures are not substantially more stable than extended conformations of cytochrome c. Using deeply trapped intermediates to map the cytochrome c folding landscape.,Tezcan FA, Findley WM, Crane BR, Ross SA, Lyubovitsky JG, Gray HB, Winkler JR Proc Natl Acad Sci U S A. 2002 Jun 25;99(13):8626-30. PMID:12084923[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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