COX5B

The enzyme weighs 14 kDa and is composed of 129 amino acids.]{{cite journal | vauthors = 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 | title = Integration of cardiac proteome biology and medicine by a specialized knowledgebase | journal = Circulation Research | volume = 113 | issue = 9 | pages = 1043–53 | date = Oct 2013 | pmid = 23965338 | pmc = 4076475 | doi = 10.1161/CIRCRESAHA.113.301151 }}{{cite web | url = https://amino.heartproteome.org/web/protein/P10606 | work = Cardiac Organellar Protein Atlas Knowledgebase (COPaKB) | title = Cytochrome c oxidase subunit 5B, mitochondrial | access-date = 2018-07-18 | archive-url = https://web.archive.org/web/20180719024525/https://amino.heartproteome.org/web/protein/P10606 | archive-date = 2018-07-19 | url-status = dead }} The protein is a subunit of Complex IV, which consists of 13 mitochondrial- and nuclear-encoded subunits. The sequence of subunit Vb is well conserved and includes three conserved cysteines that coordinate the zinc ion.{{cite journal |vauthors=Rizzuto R, Sandona D, Brini M, Capaldi RA, Bisson R |title=The most conserved nuclear-encoded polypeptide of cytochrome c oxidase is the putative zinc-binding subunit: primary structure of subunit V from the slime mold Dictyostelium discoideum |journal=Biochim. Biophys. Acta |volume=1129 |issue=1 |pages=100–104 |year=1991 |pmid=1661610 |doi=10.1016/0167-4781(91)90220-G}}{{cite journal |vauthors=Tsukihara T, Yamaguchi H, Aoyama H, Yamashita E, Tomizaki T, Shinzawa-Itoh K, Nakashima R, Yaono R, Yoshikawa S |title=The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 A |journal=Science |volume=272 |issue=5265 |pages=1136–1144 |year=1996 |pmid=8638158 |doi=10.1126/science.272.5265.1136 |bibcode=1996Sci...272.1136T|s2cid=20860573 }} Two of these cysteines are clustered in the C-terminal section of the subunit.

{{Infobox_gene}}

The COX5B gene, located on the q arm of chromosome 2 in position 11.2, is made up of 4 exons and is 2,137 base pairs in length.

Cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. It is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane to drive ATP synthesis via protonmotive force. The mitochondrially-encoded subunits perform the electron transfer of proton pumping activities. The functions of the nuclear-encoded subunits are unknown but they may play a role in the regulation and assembly of the complex.

Summary reaction:

: 4 Fe²⁺-cytochrome c + 8 H⁺_in + O₂ → 4 Fe³⁺-cytochrome c + 2 H₂O + 4 H⁺_out{{cite book|last1=Pratt|first1=Donald Voet, Judith G. Voet, Charlotte W.|title=Fundamentals of biochemistry : life at the molecular level|date=2013|publisher=Wiley|location=Hoboken, NJ|isbn=978-0-470-54784-7|chapter = 18 | pages=581–620|edition=4th}}

COX5A and COX5B are involved in the regulation of cancer cell metabolism by Bcl-2.{{cite journal | vauthors = Chen ZX, Pervaiz S | title = Involvement of cytochrome c oxidase subunits Va and Vb in the regulation of cancer cell metabolism by Bcl-2 | journal = Cell Death and Differentiation | volume = 17 | issue = 3 | pages = 408–20 | date = Mar 2010 | pmid = 19834492 | doi = 10.1038/cdd.2009.132 | doi-access = free }}

The Trans-activator of transcription protein (Tat) of human immunodeficiency virus (HIV) inhibits cytochrome c oxidase (COX) activity in permeabilized mitochondria isolated from both mouse and human liver, heart, and brain samples.{{cite journal | vauthors = Lecoeur H, Borgne-Sanchez A, Chaloin O, El-Khoury R, Brabant M, Langonné A, Porceddu M, Brière JJ, Buron N, Rebouillat D, Péchoux C, Deniaud A, Brenner C, Briand JP, Muller S, Rustin P, Jacotot E | title = HIV-1 Tat protein directly induces mitochondrial membrane permeabilization and inactivates cytochrome c oxidase | journal = Cell Death & Disease | volume = 3 | issue = 3 | pmid = 22419111 | doi = 10.1038/cddis.2012.21 | pmc=3317353 | year=2012 | pages=e282}}

COX5B has been shown to interact with Androgen receptor.{{cite journal | vauthors = Beauchemin AM, Gottlieb B, Beitel LK, Elhaji YA, Pinsky L, Trifiro MA | title = Cytochrome c oxidase subunit Vb interacts with human androgen receptor: a potential mechanism for neurotoxicity in spinobulbar muscular atrophy | journal = Brain Res. Bull. | volume = 56 | issue = 3–4 | pages = 285–97 | year = 2001 | pmid = 11719263 | doi = 10.1016/S0361-9230(01)00583-4 | s2cid = 24740136 }}

{{reflist}}

{{refbegin | 2}}

• {{cite journal | vauthors = Lomax MI, Hsieh CL, Darras BT, Francke U | title = Structure of the human cytochrome c oxidase subunit Vb gene and chromosomal mapping of the coding gene and of seven pseudogenes | journal = Genomics | volume = 10 | issue = 1 | pages = 1–9 | year = 1991 | pmid = 1646156 | doi = 10.1016/0888-7543(91)90476-U | hdl = 2027.42/29338 | hdl-access = free }}
• {{cite journal | vauthors = Romero N, Marsac C, Fardeau M, Droste M, Schneyder B, Kadenbach B | title = Immunohistochemical demonstration of fibre type-specific isozymes of cytochrome c oxidase in human skeletal muscle | journal = Histochemistry | volume = 94 | issue = 2 | pages = 211–5 | year = 1990 | pmid = 2162812 | doi = 10.1007/BF02440190 | s2cid = 33365867 }}
• {{cite journal | vauthors = Zeviani M, Sakoda S, Sherbany AA, Nakase H, Rizzuto R, Samitt CE, DiMauro S, Schon EA | title = Sequence of cDNAs encoding subunit Vb of human and bovine cytochrome c oxidase | journal = Gene | volume = 65 | issue = 1 | pages = 1–11 | year = 1988 | pmid = 2840351 | doi = 10.1016/0378-1119(88)90411-8 }}
• {{cite journal | vauthors = Hughes GJ, Frutiger S, Paquet N, Pasquali C, Sanchez JC, Tissot JD, Bairoch A, Appel RD, Hochstrasser DF | title = Human liver protein map: update 1993 | journal = Electrophoresis | volume = 14 | issue = 11 | pages = 1216–22 | year = 1993 | pmid = 8313870 | doi = 10.1002/elps.11501401181 | s2cid = 33424554 }}
• {{cite journal | vauthors = Bachman NJ, Yang TL, Dasen JS, Ernst RE, Lomax MI | title = Phylogenetic footprinting of the human cytochrome c oxidase subunit VB promoter | journal = Arch. Biochem. Biophys. | volume = 333 | issue = 1 | pages = 152–62 | year = 1996 | pmid = 8806766 | doi = 10.1006/abbi.1996.0376 }}
• {{cite journal | vauthors = Lefai E, Vincent A, Boespflug-Tanguy O, Tanguy A, Alziari S | title = Quantitative decrease of human cytochrome c oxidase during development: evidences for a post-transcriptional regulation | journal = Biochim. Biophys. Acta | volume = 1318 | issue = 1–2 | pages = 191–201 | year = 1997 | pmid = 9030264 | doi = 10.1016/S0005-2728(96)00136-3 | doi-access = }}
• {{cite journal | vauthors = Wu H, Rao GN, Dai B, Singh P | title = Autocrine gastrins in colon cancer cells Up-regulate cytochrome c oxidase Vb and down-regulate efflux of cytochrome c and activation of caspase-3 | journal = J. Biol. Chem. | volume = 275 | issue = 42 | pages = 32491–8 | year = 2000 | pmid = 10915781 | doi = 10.1074/jbc.M002458200 | doi-access = free }}
• {{cite journal | vauthors = Beauchemin AM, Gottlieb B, Beitel LK, Elhaji YA, Pinsky L, Trifiro MA | title = Cytochrome c oxidase subunit Vb interacts with human androgen receptor: a potential mechanism for neurotoxicity in spinobulbar muscular atrophy | journal = Brain Res. Bull. | volume = 56 | issue = 3–4 | pages = 285–97 | year = 2002 | pmid = 11719263 | doi = 10.1016/S0361-9230(01)00583-4 | s2cid = 24740136 }}
• {{cite journal | vauthors = 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 | title = Large-scale mapping of human protein-protein interactions by mass spectrometry | journal = Mol. Syst. Biol. | volume = 3 | issue = 1 | pages = 89 | year = 2007 | pmid = 17353931 | pmc = 1847948 | doi = 10.1038/msb4100134 }}

{{refend}}

• {{UCSC gene info|COX5B}}
• [https://web.archive.org/web/20150924025509/http://www.heartproteome.org/copa/ProteinInfo.aspx?QType=Protein%20ID&QValue=P10606 Mass spectrometry characterization of COX5B at COPaKB]
• [http://prosite.expasy.org/PDOC00663 Cytochrome c oxidase subunit Vb] in PROSITE
• {{PDBe-KB2|P10606|Cytochrome c oxidase subunit 5B, mitochondrial}}

{{NLM content}}

Category:Enzymes