MT-CO3 mitochondrially encoded cytochrome c oxidase III [Homo sapiens (human)] - Gene

Summary

Official Symbol: MT-CO3provided by HGNC
Official Full Name: mitochondrially encoded cytochrome c oxidase IIIprovided by HGNC
Primary source: HGNC:HGNC:7422
See related: MIM:516050; AllianceGenome:HGNC:7422
Gene type: protein coding
RefSeq status: PROVISIONAL
Organism: Homo sapiens
Lineage: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as: COIII; MTCO3; COX3
Summary: Predicted to contribute to cytochrome-c oxidase activity. Involved in respiratory chain complex IV assembly. Located in mitochondrion. Part of mitochondrial membrane and respiratory chain complex IV. Implicated in MELAS syndrome. [provided by Alliance of Genome Resources, Apr 2025]
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Genomic context

Annotation release	Status	Assembly	Chr	Location
RS_2024_08	current	GRCh38.p14 (GCF_000001405.40)	MT (non-nuclear)	NC_012920.1 (9207..9990)
RS_2024_09	previous assembly	GRCh37.p13 (GCF_000001405.25)	MT (non-nuclear)	NC_012920.1 (9207..9990)

Chromosome MT - NC_012920.1 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Genomic Sequence:

Go to nucleotide: Graphics FASTA GenBank

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

A lack of a definite correlation between male sub-fertility and single nucleotide polymorphisms in sperm mitochondrial genes MT-CO3, MT-ATP6 and MT-ATP8.
Title: A lack of a definite correlation between male sub-fertility and single nucleotide polymorphisms in sperm mitochondrial genes MT-CO3, MT-ATP6 and MT-ATP8.
Whole mitochondrial genome analysis in Chinese patients with keratoconus.
Title: Whole mitochondrial genome analysis in Chinese patients with keratoconus.
HIGD2A is Required for Assembly of the COX3 Module of Human Mitochondrial Complex IV.
Title: HIGD2A is Required for Assembly of the COX3 Module of Human Mitochondrial Complex IV.
The T9861C Mutation in the mtDNA-Encoded Cytochrome C Oxidase Subunit III Gene Occurs in High Frequency but with Unequal Distribution in the Alzheimer's Disease Brain.
Title: The T9861C Mutation in the mtDNA-Encoded Cytochrome C Oxidase Subunit III Gene Occurs in High Frequency but with Unequal Distribution in the Alzheimer's Disease Brain.
There was a significant association of cytochrome c oxidase III 15bp deletion with human male infertility.
Title: Sperm mitochondrial DNA 15bp deletion of cytochrome c oxidase subunit III is significantly associated with human male infertility in Pakistan.
this is the first study showing to demonstrate that aa72-117 in HBx is the key region for binding with COXIII.
Title: Accurately mapping the location of the binding site for the interaction between hepatitis B virus X protein and cytochrome c oxidase III.
A novel COIII gene m.9588G>A mutation was found in the mtDNA sperm's in all asthenozoospermic patients and was absent in the normozoospermic and in fertile men.
Title: Identification of a novel m.9588G > a missense mutation in the mitochondrial COIII gene in asthenozoospermic Tunisian infertile men.
novel heteroplasmic mutation m.9276G>C in the mitochondrial COIII gene, detected in mtDNA extracted from leukocytes of a mother and her two daughters indicating that this mutation is maternally transmitted
Title: A novel mutation MT-COIII m.9267G>C and MT-COI m.5913G>A mutation in mitochondrial genes in a Tunisian family with maternally inherited diabetes and deafness (MIDD) associated with severe nephropathy.
Lack of Cox3 limits the biosynthesis of COX but does not alter the structure of the enzyme.
Title: Alteration of structure and function of ATP synthase and cytochrome c oxidase by lack of Fo-a and Cox3 subunits caused by mitochondrial DNA 9205delTA mutation.
A novel heteroplasmic missense mitochondrial mutation (m.9387 G>A) in COXIII gene found in 3 asthenospermic patients from Tunisia.
Title: Mitochondrial DNA mutations and polymorphisms in asthenospermic infertile men.

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Phenotypes

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Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description	Tests
Leber optic atrophy MedGen: C0917796 OMIM: 535000 GeneReviews: Leber Hereditary Optic Neuropathy, Primary Mitochondrial Disorders Overview	Compare labs
MELAS syndrome MedGen: C0162671 OMIM: 540000 GeneReviews: Primary Mitochondrial Disorders Overview, MELAS	Compare labs

Variation

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See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

HIV-1 interactions

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Protein interactions

Protein	Gene	Interaction	Pubs
Tat	tat	Tat-induced mitochondrial membrane permeabilization is associated with inhibition of cytochrome c oxidase (COX) activity by Tat in disrupted mitochondria from human samples	PubMed

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Pathways from PubChem

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Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Markers

PMC109173P1 (e-PCR)
- UniSTS:270154

PMC20756P1 (e-PCR)
- UniSTS:271961

SHGC-57364 (e-PCR)
- UniSTS:67674

PMC20756P2 (e-PCR)
- UniSTS:271962

RH98513 (e-PCR)
- UniSTS:83580

D1S2077E (e-PCR)
- UniSTS:151716

PMC55343P3 (e-PCR)
- UniSTS:273326

PMC55343P4 (e-PCR)
- UniSTS:273327

PMC55343P5 (e-PCR)
- UniSTS:273328

PMC55343P6 (e-PCR)
- UniSTS:273329

PMC55343P7 (e-PCR)
- UniSTS:273330

PMC55343P8 (e-PCR)
- UniSTS:273331

PMC196577P3 (e-PCR)
- UniSTS:271816

Gene Ontology Provided by GOA

Function	Evidence Code	Pubs
contributes_to cytochrome-c oxidase activity	IBA Inferred from Biological aspect of Ancestor more info
enables cytochrome-c oxidase activity	IEA Inferred from Electronic Annotation more info
enables electron transfer activity	IEA Inferred from Electronic Annotation more info
enables protein binding	IPI Inferred from Physical Interaction more info	PubMed

Process	Evidence Code	Pubs
involved_in aerobic electron transport chain	IEA Inferred from Electronic Annotation more info
involved_in cellular respiration	NAS Non-traceable Author Statement more info	PubMed
involved_in mitochondrial electron transport, cytochrome c to oxygen	IBA Inferred from Biological aspect of Ancestor more info
involved_in mitochondrial electron transport, cytochrome c to oxygen	NAS Non-traceable Author Statement more info	PubMed
involved_in proton transmembrane transport	IEA Inferred from Electronic Annotation more info
involved_in respiratory chain complex IV assembly	IMP Inferred from Mutant Phenotype more info	PubMed
involved_in respiratory electron transport chain	IEA Inferred from Electronic Annotation more info

Component	Evidence Code	Pubs
located_in membrane	IEA Inferred from Electronic Annotation more info
is_active_in mitochondrial inner membrane	IEA Inferred from Electronic Annotation more info
located_in mitochondrial inner membrane	IEA Inferred from Electronic Annotation more info
located_in mitochondrial inner membrane	TAS Traceable Author Statement more info
located_in mitochondrial membrane	IDA Inferred from Direct Assay more info	PubMed
located_in mitochondrion	HTP more info	PubMed
is_active_in mitochondrion	IBA Inferred from Biological aspect of Ancestor more info
located_in mitochondrion	IEA Inferred from Electronic Annotation more info
part_of respiratory chain complex IV	IDA Inferred from Direct Assay more info	PubMed
part_of respiratory chain complex IV	IEA Inferred from Electronic Annotation more info