COQ3

Protein identityUniProt · HPA

UniProt accession

Q9NZJ6

Gene

COQ3

Ensembl

ENSG00000132423

Chromosome

6

Canonical length

369 aa

Protein class

Enzymes, Metabolic proteins, Predicted intracellular proteins

Subcellular location

Nucleoplasm,Mitochondria

OverviewNCBI Gene

Ubiquinone, also known as coenzyme Q, or Q, is a critical component of the electron transport pathways of both eukaryotes and prokaryotes (Jonassen and Clarke, 2000 [PubMed 10777520]). This lipid consists of a hydrophobic isoprenoid tail and a quinone head group. The tail varies in length depending on the organism, but its purpose is to anchor coenzyme Q to the membrane. The quinone head group is responsible for the activity of coenzyme Q in the respiratory chain. The S. cerevisiae COQ3 gene encodes an O-methyltransferase required for 2 steps in the biosynthetic pathway of coenzyme Q. This enzyme methylates an early coenzyme Q intermediate, 3,4-dihydroxy-5-polyprenylbenzoic acid, as well as the final intermediate in the pathway, converting demethyl-ubiquinone to coenzyme Q. The COQ3 gene product is also capable of methylating the distinct prokaryotic early intermediate 2-hydroxy-6-polyprenyl phenol.[supplied by OMIM, Mar 2008]

Canonical amino-acid sequenceUniProt

369 residues, UniProt reviewed canonical sequence.

>Q9NZJ6|COQ3
     1  MWSGRKLGSS GGWFLRVLGP GGCNTKAARP LISSAVYVKN QLSGTLQIKP GVFNEYRTIW
    61  FKSYRTIFSC LNRIKSFRYP WARLYSTSQT TVDSGEVKTF LALAHKWWDE QGVYAPLHSM
   121  NDLRVPFIRD NLLKTIPNHQ PGKPLLGMKI LDVGCGGGLL TEPLGRLGAS VIGIDPVDEN
   181  IKTAQCHKSF DPVLDKRIEY RVCSLEEIVE ETAETFDAVV ASEVVEHVID LETFLQCCCQ
   241  VLKPGGSLFI TTINKTQLSY ALGIVFSEQI ASIVPKGTHT WEKFVSPETL ESILESNGLS
   301  VQTVVGMLYN PFSGYWHWSE NTSLNYAAYA VKSRVQEHPA SAEFVLKGET EELQANACTN
   361  PAVHEKLKK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against COQ3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Other membrane

Secreted

No

Transmembrane segments

0

Mean surface accessibility (rSASA)

0.4

Highest tissue expression

48 nTPM

Expression across tissuesHPA

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

1.34

gnomAD pLI

0

gnomAD missense Z

-0.07

DepMap mean gene effect

-0.16

DepMap dependency class

selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• glycerol metabolic process
• methylation
• ubiquinone biosynthetic process

Molecular functions

• O-methyltransferase activity
• 3-demethylubiquinol 3-O-methyltransferase activity
• 3-demethylubiquinone 3-O-methyltransferase activity
• polyprenyldihydroxybenzoate methyltransferase activity

Cellular components

• extrinsic component of mitochondrial inner membrane
• mitochondrial inner membrane
• mitochondrial matrix
• mitochondrion
• ubiquinone biosynthesis complex

Protein domainsUniProt · Pfam · InterPro

• S-adenosyl-L-methionine-dependent methyltransferase superfamily
• Methyltransferase domain
• Ubiquinone biosynthesis O-methyltransferase

KeywordsUniProt

• Acetylation
• Membrane
• Methyltransferase
• Mitochondrion
• Mitochondrion inner membrane
• S-adenosyl-L-methionine
• Transferase
• Transit peptide
• Ubiquinone biosynthesis

InteractionsUniProt · HPA

Protein binding partners of COQ3 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

• COQ6
• COQ9