UQCR11

Ubiquinol-cytochrome c reductase, complex III subunit XI
Identifiers
Symbols	UQCR11 ; 0710008D09Rik; QCR10; UQCR
External IDs	OMIM: 609711 HomoloGene: 4974 GeneCards: UQCR11 Gene
Gene ontology Molecular function • ubiquinol-cytochrome-c reductase activity • electron carrier activity Cellular component • mitochondrial inner membrane • integral component of membrane • respiratory chain Biological process • generation of precursor metabolites and energy • respiratory electron transport chain • cellular metabolic process • small molecule metabolic process • hydrogen ion transmembrane transport Sources: Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	10975	66594
Ensembl	ENSG00000127540	ENSMUSG00000020163
UniProt	O14957	Q9CPX8
RefSeq (mRNA)	NM_006830	NM_025650
RefSeq (protein)	NP_006821	NP_079926
Location (UCSC)	Chr 19: 1.6 – 1.61 Mb	Chr 10: 80.4 – 80.41 Mb
PubMed search	[1]	[2]

UQCR11 (ubiquinol-cytochrome c reductase, complex III subunit XI) is a protein that in humans is encoded by the UQCR11 gene. UQCR11 is the smallest known component of Complex III in the mitochondrial respiratory chain.

Structure

The UQCR11 gene, located on the p arm of chromosome 19 in position 13.3, is made up of 3 exons and is 8,329 base pairs in length. The UQCR11 protein weighs 6.6 kDa and is composed of 56 amino acids. This gene encodes the smallest known component of the ubiquinol-cytochrome c reductase complex, which is also known as Complex III and is part of the mitochondrial respiratory chain. In vertebrates, Complex III contains 11 subunits: 3 respiratory subunits, 2 core proteins and 6 low-molecular weight proteins. Proteobacterial complexes may contain as few as three subunits.

Function

The UQCR11 protein may function as a binding factor for the iron-sulfur protein in Complex III, which is ubiquitous in human cells. Complex III catalyzes the chemical reaction

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

Thus, the two substrates of Complex III are dihydroquinone (QH2) and ferri- (Fe³⁺) cytochrome c, whereas its 3 products are quinone (Q), ferro- (Fe²⁺) cytochrome c, and H⁺. This complex belongs to the family of oxidoreductases, specifically those acting on diphenols and related substances as donor with a cytochrome as acceptor. This enzyme participates in oxidative phosphorylation. It has four cofactors: cytochrome c₁, cytochrome b-562, cytochrome b-566 and a 2-Iron ferredoxin of the Rieske type.

References

This article incorporates text from the United States National Library of Medicine, which is in the public domain.