The enzyme cytochrome c oxidase or Complex IV, is a large transmembrane protein complex found in bacteria, archaea, and mitochondria of eukaryotes.
Cytochrome c oxidase subunit III (COX3) is an enzyme that in humans is encoded by the MT-CO3 gene. It is one of main transmembrane subunits of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits of respiratory complex IV. Variants of it have been associated with isolated myopathy, severe encephalomyopathy, Leber hereditary optic neuropathy, mitochondrial complex IV deficiency, and recurrent myoglobinuria.
SCO2 cytochrome c oxidase assembly is a protein that in humans is encoded by the SCO2 gene. The encoded protein is one of the cytochrome c oxidase (COX)(Complex IV) assembly factors. Human COX is a multimeric protein complex that requires several assembly factors. Cytochrome c oxidase (COX) catalyzes the transfer of electrons from cytochrome c to molecular oxygen, which helps to maintain the proton gradient across the inner mitochondrial membrane that is necessary for aerobic ATP production. The encoded protein is a metallochaperone that is involved in the biogenesis of cytochrome c oxidase subunit II. Mutations in this gene are associated with fatal infantile encephalocardiomyopathy and myopia 6.
Cytochrome c oxidase subunit 4 isoform 1, mitochondrial (COX4I1) is an enzyme that in humans is encoded by the COX4I1 gene. COX4I1 is a nuclear-encoded isoform of cytochrome c oxidase (COX) subunit 4. Cytochrome c oxidase 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, acting as the terminal enzyme of the mitochondrial respiratory chain. Antibodies against COX4 can be used to identify the inner membrane of mitochondria in immunofluorescence studies. Mutations in COX4I1 have been associated with COX deficiency and Fanconi anemia.
Cytochrome c oxidase subunit 4 isoform 2, mitochondrial is an enzyme that in humans is encoded by the COX4I2 gene. COX4I2 is a nuclear-encoded isoform of cytochrome c oxidase (COX) subunit 4. Cytochrome c oxidase 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, acting as the terminal enzyme of the mitochondrial respiratory chain. Mutations in COX4I2 have been associated with exocrine pancreatic insufficiency, dyserythropoietic anemia, and calvarial hyperostosis (EPIDACH).
Cytochrome c oxidase subunit 6B1 is an enzyme that in humans is encoded by the COX6B1 gene. 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).
Protoheme IX farnesyltransferase, mitochondrial is an enzyme that in humans is encoded by the COX10 gene. Cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced cytochrome c to oxygen. This component 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 function in the regulation and assembly of the complex. This nuclear gene, COX10, encodes heme A: farnesyltransferase, which is not a structural subunit but required for the expression of functional COX and functions in the maturation of the heme A prosthetic group of COX. A gene mutation, which results in the substitution of a lysine for an asparagine (N204K), is identified to be responsible for cytochrome c oxidase deficiency. In addition, this gene is disrupted in patients with CMT1A duplication and with HNPP deletion.
Cytochrome c oxidase subunit 5B, mitochondrial is an enzyme in humans that is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. In humans, cytochrome c oxidase subunit 5B is encoded by the COX5B gene.
Cytochrome c oxidase subunit 6A1, mitochondrial is a protein that in humans is encoded by the COX6A1 gene. Cytochrome c oxidase 6A1 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. A mutation of the COX6A1 gene is associated with a recessive axonal or mixed form of Charcot-Marie-Tooth disease.
Cytochrome c oxidase subunit 7B, mitochondrial (COX7B) is an enzyme that in humans is encoded by the COX7B gene. COX7B is a nuclear-encoded subunit of cytochrome c oxidase (COX). Cytochrome c oxidase 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, acting as the terminal enzyme of the mitochondrial respiratory chain. Work with Oryzias latices has linked disruptions in COX7B with microphthalmia with linear skin lesions (MLS), microcephaly, and mitochondrial disease. Clinically, mutations in COX7B have been associated with linear skin defects with multiple congenital anomalies.
Cytochrome c oxidase subunit 7A-related protein, mitochondrial is an enzyme that in humans is encoded by the COX7A2L gene.
Cytochrome c oxidase subunit 6C is an enzyme that in humans is encoded by the COX6C gene.
Cytochrome c oxidase subunit 5a is a protein that in humans is encoded by the COX5A gene. Cytochrome c oxidase 5A is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.
Cytochrome c oxidase subunit VIa polypeptide 2 is a protein that in humans is encoded by the COX6A2 gene. Cytochrome c oxidase 6A2 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.
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.
NDUFA4, mitochondrial complex associated is a protein that in humans is encoded by the NDUFA4 gene. The NDUFA4 protein was first described to be a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. However, recent research has described NDUFA4 as a subunit of cytochrome c oxidase. Mutations in the NDUFA4 gene are associated with Leigh's syndrome.
Cytochrome c oxidase assembly factor 3, also known as Coiled-coil domain-containing protein 56, or Mitochondrial translation regulation assembly intermediate of cytochrome c oxidase protein of 12 kDa is a protein that in humans is encoded by the COA3 gene. This gene encodes a member of the cytochrome c oxidase assembly factor family. Studies of a related gene in fly suggest that the encoded protein is localized to mitochondria and is essential for cytochrome c oxidase function.
Cytochrome c oxidase assembly factor COX14 is a protein that in humans is encoded by the COX14 gene. This gene encodes a small single-pass transmembrane protein that localizes to mitochondria. This protein may play a role in coordinating the early steps of cytochrome c oxidase subunit assembly and, in particular, the synthesis and assembly of the COX I subunit of the holoenzyme. Mutations in this gene have been associated with mitochondrial complex IV deficiency. Alternative splicing results in multiple transcript variants.
Cytochrome c oxidase assembly factor 6 is a protein that in humans is encoded by the COA6 gene. Mitochondrial respiratory chain Complex IV, or cytochrome c oxidase, is the component of the respiratory chain that catalyzes the transfer of electrons from intermembrane space cytochrome c to molecular oxygen in the matrix and as a consequence contributes to the proton gradient involved in mitochondrial ATP synthesis. The COA6 gene encodes an assembly factor for mitochondrial complex IV and is a member of the cytochrome c oxidase subunit 6B family. This protein is located in the intermembrane space, associating with SCO2 and COX2. It stabilizes newly formed COX2 and is part of the mitochondrial copper relay system. Mutations in this gene result in fatal infantile cardioencephalomyopathy.
PET100 homolog is a protein that in humans is encoded by the PET100 gene. Mitochondrial complex IV, or cytochrome c oxidase, is a large transmembrane protein complex that is part of the respiratory electron transport chain of mitochondria. The small protein encoded by the PET100 gene plays a role in the biogenesis of mitochondrial complex IV. This protein localizes to the inner mitochondrial membrane and is exposed to the intermembrane space. Mutations in this gene are associated with mitochondrial complex IV deficiency. This gene has a pseudogene on chromosome 3. Alternative splicing results in multiple transcript variants.
