Mitochondrial complex III - core subunits are ubiquinol-cytochrome c reductases that act to catalyze the electron transfer reaction from the lipophilic substrate ubiquinol (QH2) to cytochrome C (cyt c), coupled with proton translocation across the membrane. As a result, for every QH2 molecule oxidized, four protons are transferred from the mitochondrial matrix to the intermembrane space and two molecules of cyt c are reduced. The subunit composition of complex III varies between species, though all complexes contain three redox subunits that form the catalytic core: cyt b; cyt c1; and the iron sulfur (Rieske) protein (ISP). (Adapted from PMID:23201476 and PMID: 23871937.)
Notes on Group
Cyt-c1 and Cyt-c1L are paralogous genes in D. melanogaster. Cyt-c1 has widespread expression, whereas Cyt-c1L is expressed specifically in the testis.
