1s6v
Structure of a cytochrome c peroxidase-cytochrome c site specific cross-linkStructure of a cytochrome c peroxidase-cytochrome c site specific cross-link
Structural highlights
FunctionCYC1_YEAST 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 PubMedA specific covalently cross-linked complex between redox partners yeast cytochrome c peroxidase (CCP) and cytochrome c (cyt. c) has been made by engineering cysteines into CCP and cyt. c that form an intermolecular disulfide bond in high yield. The crystal structure of the cross-linked complex has been solved to 1.88-A resolution and closely resembles the structure of the noncovalent complex [Pellitier, H. & Kraut, J. (1992) Science 258, 1748-1755]. The higher resolution of the covalent complex has enabled the location of ordered water molecules at the peroxidase-cytochrome c interface that serve to bridge between the two proteins by hydrogen bonding. As in the noncovalent complex, direct electrostatic interactions between protein groups appear not to be critical in complex formation. UV-visible spectroscopic and stopped-flow studies indicate that CCP in the covalent complex reacts normally with H(2)O(2) to give compound I. Stopped-flow kinetic studies also show that intramolecular electron transfer between the cross-linked ferrocytochrome c and the Trp-191 cation radical site in CCP compound I occurs fast and is nearly complete within the dead time ( approximately 2 ms) of the instrument. These results indicate that the structure of the covalent complex closely mimics the physiological electron transfer complex. In addition, single-turnover and steady-state experiments reveal that CCP compound I in the covalent complex oxidizes exogenously added ferrocytochrome c at a slow rate (t(1/2) approximately 2 min), indicating that CCP does not have a second independent site for physiologically relevant electron transfer. Crystal structure and characterization of a cytochrome c peroxidase-cytochrome c site-specific cross-link.,Guo M, Bhaskar B, Li H, Barrows TP, Poulos TL Proc Natl Acad Sci U S A. 2004 Apr 20;101(16):5940-5. Epub 2004 Apr 7. PMID:15071191[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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