COX6B1

COX6B1
Identifiers
Aliases	COX6B1, COX6B, COXG, COXVIb1, cytochrome c oxidase subunit 6B1
External IDs	MGI: 107460 HomoloGene: 39658 GeneCards: COX6B1
Gene ontology Molecular function • cytochrome-c oxidase activity Cellular component • mitochondrial inner membrane • mitochondrial intermembrane space • mitochondrion Biological process • substantia nigra development • mitochondrial electron transport, cytochrome c to oxygen • hydrogen ion transmembrane transport Sources:Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	1340	110323
Ensembl	ENSG00000126267	ENSMUSG00000036751
UniProt	P14854	P56391
RefSeq (mRNA)	NM_001863	NM_025628
RefSeq (protein)	NP_001854.1	NP_079904.1
Location (UCSC)	Chr 19: 35.65 – 35.66 Mb	Chr 7: 30.62 – 30.63 Mb
PubMed search	[1]	[2]
Wikidata

View/Edit Human

View/Edit Mouse

Cytochrome c oxidase subunit 6B1 is an enzyme that in humans is encoded by the COX6B1 gene.^[3] Cytochrome c oxidase 6B1 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. Mutations of the COX6B1 gene are associated with severe infantile encephalomyopathy and mitochondrial complex IV deficiency (MT-C4D).^[4]

Structure

The COX6B1 gene, located on the q arm of chromosome 19 in position 13.1, contains 4 exons and is 10,562 base pairs in length.^[4] The COX6B1 protein weighs 10 kDa and is composed of 86 amino acids.^[5][6] The protein is a subunit of Complex IV, a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes.^[4]

Function

Cytochrome c oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced cytochrome c to oxygen. It is a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. The mitochondrially-encoded subunits function in electron transfer, and the nuclear-encoded subunits may be involved in the regulation and assembly of the complex. This nuclear gene encodes subunit VIb. Three pseudogenes COX6BP-1, COX6BP-2 and COX6BP-3 have been found on chromosomes 7, 17 and 22q13.1-13.2, respectively.^[4]

Summary reaction:

4 Fe²⁺-cytochrome c + 8 H⁺_in + O₂ → 4 Fe³⁺-cytochrome c + 2 H₂O + 4 H⁺_out^[7]

Clinical significance

Mutations affecting the COX6B1 gene are associated with mitochondrial complex IV deficiency (MT-C4D), a disorder of the mitochondrial respiratory chain with heterogeneous clinical manifestations, ranging from isolated myopathy to severe multisystem disease affecting several tissues and organs. Features include hypertrophic cardiomyopathy, hepatomegaly and liver dysfunction, hypotonia, muscle weakness, exercise intolerance, developmental delay, delayed motor development and mental retardation. Some affected individuals manifest a fatal hypertrophic cardiomyopathy resulting in neonatal death. A subset of patients manifest Leigh's syndrome.^[8]

References

1. "Human PubMed Reference:".
2. "Mouse PubMed Reference:".
3. Taanman JW, van der Veen AY, Schrage C, de Vries H, Buys CH (Jul 1991). "Assignment of the gene coding for human cytochrome c oxidase subunit VIb to chromosome 19, band q13.1, by fluorescence in situ hybridisation". Human Genetics. 87 (3): 325–7. doi:10.1007/bf00200913. PMID 1650756.
4. "Entrez Gene: COX6B1 cytochrome c oxidase subunit Vib polypeptide 1 (ubiquitous)".
5. Zong NC, Li H, Li H, Lam MP, Jimenez RC, Kim CS, Deng N, Kim AK, Choi JH, Zelaya I, Liem D, Meyer D, Odeberg J, Fang C, Lu HJ, Xu T, Weiss J, Duan H, Uhlen M, Yates JR, Apweiler R, Ge J, Hermjakob H, Ping P (Oct 2013). "Integration of cardiac proteome biology and medicine by a specialized knowledgebase". Circulation Research. 113 (9): 1043–53. doi:10.1161/CIRCRESAHA.113.301151. PMC 4076475. PMID 23965338.
6. "Cytochrome c oxidase subunit 6B1". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).
7. Voet D, Voet JG, Pratt CW (2013). "Chapter 18". Fundamentals of biochemistry: life at the molecular level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN 978-0-470-54784-7.
8. "COX6B1". Genetics Home Reference. U.S. National Library of Medicine. Retrieved 3 April 2015.

Further reading

• Taanman JW, Schrage C, Bokma E, Reuvekamp P, Agsteribbe E, De Vries H (Jun 1991). "Nucleotide sequence of the last exon of the gene for human cytochrome c oxidase subunit VIb and its flanking regions". Biochimica et Biophysica Acta. 1089 (2): 283–5. doi:10.1016/0167-4781(91)90027-J. PMID 1647217.
• Carrero-Valenzuela RD, Quan F, Lightowlers R, Kennaway NG, Litt M, Forte M (Jun 1991). "Human cytochrome c oxidase subunit VIb: characterization and mapping of a multigene family". Gene. 102 (2): 229–36. doi:10.1016/0378-1119(91)90082-M. PMID 1651883.
• Taanman JW, Schrage C, Ponne NJ, Das AT, Bolhuis PA, de Vries H, Agsteribbe E (Sep 1990). "Isolation of cDNAs encoding subunit VIb of cytochrome c oxidase and steady-state levels of coxVIb mRNA in different tissues". Gene. 93 (2): 285–91. doi:10.1016/0378-1119(90)90237-L. PMID 2172092.
• Taanman JW, Schrage C, Ponne N, Bolhuis P, de Vries H, Agsteribbe E (Feb 1989). "Nucleotide sequence of cDNA encoding subunit VIb of human cytochrome c oxidase". Nucleic Acids Research. 17 (4): 1766. doi:10.1093/nar/17.4.1766. PMC 331842. PMID 2537962.
• Kato S, Sekine S, Oh SW, Kim NS, Umezawa Y, Abe N, Yokoyama-Kobayashi M, Aoki T (Dec 1994). "Construction of a human full-length cDNA bank". Gene. 150 (2): 243–50. doi:10.1016/0378-1119(94)90433-2. PMID 7821789.
• Schmidt TR, Goodman M, Grossman LI (Mar 2002). "Amino acid replacement is rapid in primates for the mature polypeptides of COX subunits, but not for their targeting presequences". Gene. 286 (1): 13–9. doi:10.1016/S0378-1119(01)00800-9. PMID 11943455.
• Ewing RM, Chu P, Elisma F, Li H, Taylor P, Climie S, McBroom-Cerajewski L, Robinson MD, O'Connor L, Li M, Taylor R, Dharsee M, Ho Y, Heilbut A, Moore L, Zhang S, Ornatsky O, Bukhman YV, Ethier M, Sheng Y, Vasilescu J, Abu-Farha M, Lambert JP, Duewel HS, Stewart II, Kuehl B, Hogue K, Colwill K, Gladwish K, Muskat B, Kinach R, Adams SL, Moran MF, Morin GB, Topaloglou T, Figeys D (2007). "Large-scale mapping of human protein-protein interactions by mass spectrometry". Molecular Systems Biology. 3 (1): 89. doi:10.1038/msb4100134. PMC 1847948. PMID 17353931.
• Sirchia R, Luparello C (May 2007). "Mid-region parathyroid hormone-related protein (PTHrP) and gene expression of MDA-MB231 breast cancer cells". Biological Chemistry. 388 (5): 457–65. doi:10.1515/BC.2007.059. PMID 17516841.

External links

• Mass spectrometry characterization of COX6B1 at COPaKB

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