Atypical kinase involved in the biosynthesis of coenzyme Q, also named ubiquinone, an essential lipid-soluble electron transporter for aerobic cellular respiration. Its substrate specificity is unclear: either acts as protein kinase that phosphorylates other proteins in the CoQ complex to stabilize their interactions or acts as a small molecule kinase that phosphorylates a prenyl lipid in the ubiquinone biosynthesis pathway. Cofactor biosynthesis; ubiquinone biosynthesis. Belongs to the protein kinase superfamily. ADCK protein kinase family.