UQCRC1 is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. This protein may mediate formation of the complex between cytochromes c and c1. Recombinant human UQCRC1 protein, fused to His-tag at N-terminus, was expressed in E.coli.