UQCR11

UQCR11 (ubiquinol-cytochrome c reductase, complex III sub-unit XI) is a protein that in humans is encoded by the UQCR11 gene.^[5][6] UQCR11 is the smallest known component of Complex III in the mitochondrial respiratory chain.^[6]

UQCR11
Identifiers
Aliases	UQCR11, 0710008D09Rik, QCR10, UQCR, ubiquinol-cytochrome c reductase, complex III subunit XI
External IDs	OMIM: 609711; MGI: 1913844; HomoloGene: 4974; GeneCards: UQCR11; OMA:UQCR11 - orthologs
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19p13.3 Start 1,597,169 bp[1] End 1,605,473 bp[1]
Gene location (Mouse) Chr. Chromosome 10 (mouse)[2] Band 10|10 C1 Start 80,238,831 bp[2] End 80,242,664 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in apex of heart right auricle of heart muscle of thigh mucosa of transverse colon gastrocnemius muscle right adrenal gland right lobe of liver muscle layer of sigmoid colon left adrenal cortex cingulate gyrus Top expressed in right kidney white adipose tissue proximal tubule striatum of neuraxis adrenal gland muscle tissue quadriceps femoris muscle skeletal muscle tissue urinary bladder muscle of thigh More reference expression data BioGPS n/a
Gene ontology Molecular function electron transfer activity ubiquinol-cytochrome-c reductase activity Cellular component integral component of membrane respirasome membrane mitochondrion mitochondrial inner membrane Biological process generation of precursor metabolites and energy electron transport chain mitochondrial electron transport, ubiquinol to cytochrome c 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: 80.24 – 80.24 Mb PubMed search [3] [4]
Wikidata
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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.^[6] The UQCR11 protein weighs 6.6 kDa and is composed of 56 amino acids.^[7][8] 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.^[6] In vertebrates, Complex III contains 11 sub-units: 3 respiratory sub-units, 2 core proteins and 6 low-molecular weight proteins.^[9][10] Proteobacterial complexes may contain as few as three sub-units.^[11]

Function

The UQCR11 protein may function as a binding factor for the iron-sulfur protein in Complex III, which is ubiquitous in human cells.^[6] Complex III catalyzes the chemical reaction

QH₂ + 2 ferricytochrome c ${\displaystyle \rightleftharpoons }$ 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.