Ubiquinol-cytochrome c reductase binding protein, also known as UQCRB, is a protein which in humans is encoded by the UQCRB gene.

This gene encodes a protein which is part of the ubiquinol-cytochrome c oxidoreductase complex which contains ten nuclear-encoded and one mitochondrial-encoded subunits. The encoded protein binds ubiquinone and participates in the transfer of electrons when ubiquinone is bound. Mutations in this gene are associated with mitochondrial complex III deficiency. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. A pseudogene has been described on the X chromosome. [provided by RefSeq].
Function: This 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 component is involved in redox-linked proton pumping.