COX6B2 explained

Cytochrome c oxidase subunit VIb polypeptide 2 is a protein that in humans is encoded by the COX6B2 gene. Cytochrome c oxidase 6B2 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.^[1]

Structure

The COX6B2 gene, located on the q arm of chromosome 19 in position 13.42, contains 5 exons and is 5,113 base pairs in length. The protein encoded by the COX6B2 gene weighs 11 kDa and is composed of 88 amino acids.^{[2] [3]} 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.

Function

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 molecular 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^[4]

Further reading

• Taanman JW, Schrage C, Ponne NJ, Das AT, Bolhuis PA, de Vries H, Agsteribbe E . 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 . Sep 1990 . 2172092 . 10.1016/0378-1119(90)90237-l.
• Hüttemann M, Jaradat S, Grossman LI . Cytochrome c oxidase of mammals contains a testes-specific isoform of subunit VIb--the counterpart to testes-specific cytochrome c? . Molecular Reproduction and Development . 66 . 1 . 8–16 . Sep 2003 . 12874793 . 10.1002/mrd.10327 . 45002095 .

External links

• • Mass spectrometry characterization of COX6B2 at COPaKB

Notes and References

1. Web site: Entrez Gene: Cytochrome c oxidase subunit VIb polypeptide 2 .
2. 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 . Integration of cardiac proteome biology and medicine by a specialized knowledgebase . Circulation Research . 113 . 9 . 1043–53 . Oct 2013 . 23965338 . 4076475 . 10.1161/CIRCRESAHA.113.301151 .
3. Web site: Cytochrome c oxidase subunit VIb polypeptide 2 . Cardiac Organellar Protein Atlas Knowledgebase (COPaKB) . 2018-07-18 . https://web.archive.org/web/20180719161725/https://amino.heartproteome.org/web/protein/Q6YFQ2 . 2018-07-19 . dead .
4. Book: Donald . Voet . Judith G. . Voet . Charlotte W. . Pratt . vanc . Donald Voet . Judith G. Voet . Fundamentals of biochemistry: life at the molecular level . 2013 . Wiley . Hoboken, NJ . 978-0-470-54784-7 . Chapter 18 . 581–620 . 4th .