Cytochrome bc1 complex

spinqualitylabelsall models Cytochrome bc1 containing Cb (green), Cc1 (yellow), RISP (beige) and Fe2S2 complex with stigmatellin (PDB entry 1zrt) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Cytochrome bc1 (Cbc1) functions as the central pump which transfers protons across the cell membrane. The protons are used to power the rotation of ATP synthase. Cbc1 binds ubiquinol which carries hydrogen atoms. Cbc1 separates the protons and the electrons. The protons are released in the inner side of the membrane for use by ATP synthase and the electrons are transferred to cytochrome c or to the outer side of the membrane. Plants use cytochrome b6f in the same manner binding plastoquinol as a hydrogen carrier. Stigmatellin inhibits the Cbc1 electron transfer by binding to its quinone oxidation site. Antimycin inhibits Cbc1 by binding to its quinone reduction site. More details in Complex III of Electron Transport Chain. Structural highlights Cbc1 is a dimeric protein composed of 11 proteins and cofactors which include heme-carrying proteins like cytochrome b (Cb) and cytochrome c1 (Cc1) and iron-sulfur cluster proteins like Rieske Fe-S protein (RISP). The iron containing moieties are heme, heme C (where vinyl side chain of heme are replaced by thioether) and Fe2S2.

3D structures of cytochrome bc1

Complex III of Electron Transport Chain

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