Ubiquinol-cytochrome-c reductase

In enzymology, an ubiquinol---cytochrome-c reductase is an enzyme that catalyzes the chemical reaction


 * QH2 + 2 ferricytochrome c $$\rightleftharpoons$$ Q + 2 ferrocytochrome c + 2 H+

Thus, the two substrates of this enzyme are QH2 and ferricytochrome c, whereas its 3 products are Q, ferrocytochrome c, and H+.

This enzyme belongs to the family of oxidoreductases, specifically those acting on diphenols and related substances as donor with a cytochrome as acceptor. The systematic name of this enzyme class is ubiquinol:ferricytochrome-c oxidoreductase. Other names in common use include coenzyme Q-cytochrome c reductase, dihydrocoenzyme Q-cytochrome c reductase, reduced ubiquinone-cytochrome c reductase, complex III, (mitochondrial electron transport), ubiquinone-cytochrome c reductase, ubiquinol-cytochrome c oxidoreductase, reduced coenzyme Q-cytochrome c reductase, ubiquinone-cytochrome c oxidoreductase, reduced ubiquinone-cytochrome c oxidoreductase, mitochondrial electron transport complex III, ubiquinol-cytochrome c-2 oxidoreductase, ubiquinone-cytochrome b-c1 oxidoreductase, ubiquinol-cytochrome c2 reductase, ubiquinol-cytochrome c1 oxidoreductase, CoQH2-cytochrome c oxidoreductase, ubihydroquinol:cytochrome c oxidoreductase, coenzyme QH2-cytochrome c reductase, and QH2:cytochrome c oxidoreductase. This enzyme participates in oxidative phosphorylation. It has 4 cofactors: cytochrome c1, Cytochrome b-562, Cytochrome b-566, and 2-Iron ferredoxin.

Structural studies
As of late 2007, 35 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , and.