Structural highlights
Function
[CYC_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).
Publication Abstract from PubMed
The respiratory chain complexes can arrange into multienzyme assemblies, so-called supercomplexes. We present the first 3D map of a respiratory chain supercomplex. It was determined by random conical tilt electron microscopy analysis of a bovine supercomplex consisting of complex I, dimeric complex III, and complex IV (I1III2IV1). Within this 3D map the positions and orientations of all the individual complexes in the supercomplex were determined unambiguously. Furthermore, the ubiquinone and cytochrome c binding sites of each complex in the supercomplex could be located. The mobile electron carrier binding site of each complex was found to be in proximity to the binding site of the succeeding complex in the respiratory chain. This provides structural evidence for direct substrate channeling in the supercomplex assembly with short diffusion distances for the mobile electron carriers.
Three-dimensional structure of the respiratory chain supercomplex I1III2IV1 from bovine heart mitochondria.,Schafer E, Dencher NA, Vonck J, Parcej DN Biochemistry. 2007 Nov 6;46(44):12579-85. Epub 2007 Oct 10. PMID:17927210[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Schafer E, Dencher NA, Vonck J, Parcej DN. Three-dimensional structure of the respiratory chain supercomplex I1III2IV1 from bovine heart mitochondria. Biochemistry. 2007 Nov 6;46(44):12579-85. Epub 2007 Oct 10. PMID:17927210 doi:10.1021/bi700983h
