COX6B2

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.^[5]

COX6B2
Identifiers
Aliases	COX6B2, COXVIB2, CT59, cytochrome c oxidase subunit 6B2
External IDs	OMIM: 618127; MGI: 3044182; HomoloGene: 16948; GeneCards: COX6B2; OMA:COX6B2 - orthologs
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19q13.42 Start 55,349,306 bp[1] End 55,354,719 bp[1]
Gene location (Mouse) Chr. Chromosome 7 (mouse)[2] Band 7|7 A1 Start 4,754,791 bp[2] End 4,756,093 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right testis left testis buccal mucosa cell transverse colon mucosa of transverse colon testicle gonad olfactory zone of nasal mucosa rectum skin of abdomen Top expressed in bone marrow spermatocyte spermatid yolk sac primary oocyte testicle secondary oocyte embryonic cell urinary bladder zygote More reference expression data BioGPS n/a
Gene ontology Molecular function protein binding Cellular component mitochondrial intermembrane space mitochondrial crista mitochondrion Biological process proton transmembrane transport Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 125965 333182 Ensembl ENSG00000160471 ENSMUSG00000051811 UniProt Q6YFQ2 Q80ZN9 RefSeq (mRNA) NM_144613 NM_001289848 NM_001289849 NM_001289850 NM_183405 NM_183406 RefSeq (protein) NP_653214 NP_001356727 NP_001356728 NP_001356729 NP_001276777 NP_001276778 NP_001276779 NP_899664 NP_899665 Location (UCSC) Chr 19: 55.35 – 55.35 Mb Chr 7: 4.75 – 4.76 Mb PubMed search [3] [4]
Wikidata
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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.^[5] The protein encoded by the COX6B2 gene weighs 11 kDa and is composed of 88 amino acids.^[6][7] 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.^[5]

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.^[5]

Summary reaction:

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