Coenzyme Q7, hydroxylase (COQ7)

Coenzyme Q7, hydroxylase (COQ7) is a mitochondrial, di-iron-dependent oxidoreductase enzyme essential for the penultimate step in the biosynthesis of coenzyme Q (ubiquinone), a vital component of the electron transport chain and cellular oxidoreductive metabolism. COQ7 catalyzes the C6-hydroxylation of demethoxyubiquinone, a precursor to ubiquinone, via a substrate-mediated electron reduction pathway requiring NADH and its di-iron center. Deficiency of COQ7 activity results in accumulation of demethoxyubiquinone and clinical features of mitochondrial dysfunction, including primary coenzyme Q10 deficiency, cardiomyopathy, and neuromuscular disorders. Besides its mitochondrial function, COQ7 may translocate to the nucleus under stress and participate in retrograde signaling to regulate gene expression in response to mitochondrial redox status. COQ7 is highly conserved across eukaryotes and is required for lifespan determination, embryonic development, and regulation of reactive oxygen species.

Other names

CLK-1CAT53-demethoxyubiquinone 3-hydroxylase (NADH)Timing protein clk-1 homologUbiquinone biosynthesis monooxygenase COQ75-demethoxyubiquinone hydroxylaseCOQ7 coenzyme Q 7 homologDMQ hydroxylasecoenzyme Q biosynthesis protein 7 homologcoenzyme Q7 homologubiquinone biosynthesis protein COQ7 homolog

Inhibition of COQ7 results in decreased ubiquinone synthesis and accumulation of upstream metabolic intermediates (e.g., demethoxyubiquinone). Iron chelation impairs the di-iron enzyme activity of COQ7, blocking CoQ production.