U.S. flag

An official website of the United States government


Send to:

Choose Destination

COX5A cytochrome c oxidase subunit 5A [ Homo sapiens (human) ]

Gene ID: 9377, updated on 29-Mar-2023


Official Symbol
COX5Aprovided by HGNC
Official Full Name
cytochrome c oxidase subunit 5Aprovided by HGNC
Primary source
See related
Ensembl:ENSG00000178741 MIM:603773; AllianceGenome:HGNC:2267
Gene type
protein coding
RefSeq status
Homo sapiens
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as
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. The complex consists of 13 mitochondrial- and nuclear-encoded subunits. 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. This gene encodes the nuclear-encoded subunit Va of the human mitochondrial respiratory chain enzyme. A pseudogene COX5AP1 has been found in chromosome 14q22. [provided by RefSeq, Jul 2008]
Broad expression in heart (RPKM 144.5), colon (RPKM 144.4) and 25 other tissues See more
Try the new Gene table
Try the new Transcript table

Genomic context

See COX5A in Genome Data Viewer
Exon count:
Annotation release Status Assembly Chr Location
RS_2023_03 current GRCh38.p14 (GCF_000001405.40) 15 NC_000015.10 (74919791..74938073, complement)
RS_2023_03 current T2T-CHM13v2.0 (GCF_009914755.1) 15 NC_060939.1 (72789676..72807970, complement)
105.20220307 previous assembly GRCh37.p13 (GCF_000001405.25) 15 NC_000015.9 (75212132..75230414, complement)

Chromosome 15 - NC_000015.10Genomic Context describing neighboring genes Neighboring gene family with sequence similarity 219 member B Neighboring gene H3K27ac hESC enhancer GRCh37_chr15:75197802-75198608 Neighboring gene H3K27ac hESC enhancer GRCh37_chr15:75198609-75199413 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr15:75246929-75247862 Neighboring gene H3K27ac-H3K4me1 hESC enhancer GRCh37_chr15:75247863-75248796 Neighboring gene ribonuclease P and MRP subunit p25

Genomic regions, transcripts, and products


  • Project title: HPA RNA-seq normal tissues
  • Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
  • BioProject: PRJEB4337
  • Publication: PMID 24309898
  • Analysis date: Wed Apr 4 07:08:55 2018


GeneRIFs: Gene References Into Functions

What's a GeneRIF?


Associated conditions

Description Tests
Mitochondrial complex 4 deficiency, nuclear type 20
MedGen: C5436726 OMIM: 619064 GeneReviews: Not available
not available

EBI GWAS Catalog

Genome-wide meta-analysis identifies regions on 7p21 (AHR) and 15q24 (CYP1A2) as determinants of habitual caffeine consumption.
EBI GWAS Catalog

HIV-1 interactions

Protein interactions

Protein Gene Interaction Pubs
Envelope transmembrane glycoprotein gp41 env HIV-1 gp41 is identified to have a physical interaction with cytochrome c oxidase subunit Va (COX5A) in human HEK293 and/or Jurkat cell lines by using affinity tagging and purification mass spectrometry analyses PubMed
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

Go to the HIV-1, Human Interaction Database

Pathways from PubChem


Products Interactant Other Gene Complex Source Pubs Description

General gene information


Gene Ontology Provided by GOA

Function Evidence Code Pubs
enables cytochrome-c oxidase activity TAS
Traceable Author Statement
more info
enables electron transfer activity TAS
Traceable Author Statement
more info
enables metal ion binding IEA
Inferred from Electronic Annotation
more info
enables protein binding IPI
Inferred from Physical Interaction
more info

General protein information

Preferred Names
cytochrome c oxidase subunit 5A, mitochondrial
cytochrome c oxidase polypeptide Va
cytochrome c oxidase polypeptide, mitochondrial
cytochrome c oxidase subunit Va
mitochondrial cytochrome c oxidase subunit Va

NCBI Reference Sequences (RefSeq)

NEW Try the new Transcript table

RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

mRNA and Protein(s)

  1. NM_004255.4NP_004246.2  cytochrome c oxidase subunit 5A, mitochondrial precursor

    See identical proteins and their annotated locations for NP_004246.2

    Status: REVIEWED

    Source sequence(s)
    AC125435, AI815421, AK026623
    Consensus CDS
    P20674, Q8TB65
    ENSP00000317780.6, ENST00000322347.11
    Conserved Domains (1) summary
    Cyt_c_Oxidase_Va; Cytochrome c oxidase subunit Va. Cytochrome c oxidase (CcO), the terminal oxidase in the respiratory chains of eukaryotes and most bacteria, is a multi-chain transmembrane protein located in the inner membrane of mitochondria and the cell membrane of ...

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2023_03

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCh38.p14 Primary Assembly


  1. NC_000015.10 Reference GRCh38.p14 Primary Assembly

    74919791..74938073 complement
    GenBank, FASTA, Sequence Viewer (Graphics)

Alternate T2T-CHM13v2.0


  1. NC_060939.1 Alternate T2T-CHM13v2.0

    72789676..72807970 complement
    GenBank, FASTA, Sequence Viewer (Graphics)