The QCR10 family of proteins are a component of the ubiquinol-cytochrome c reductase complex (also known as complex III or cytochrome b-c1 complex). This complex is located on the inner mitochondrial membrane and it couples electron transfer from ubiquinol to cytochrome. This subunit (QCR10) is required for stable association of the iron-sulfur protein with the complex [1].

1: Isolation and characterization of QCR10, the nuclear gene encoding the 8.5-kDa subunit 10 of the Saccharomyces cerevisiae cytochrome bc1 complex. Brandt U, Uribe S, Schagger H, Trumpower BL; J Biol Chem. 1994;269:12947-12953. PMID:8175712