Atypical kinase involved in the biosynthesis of coenzyme Q, also named ubiquinone, an essential lipid-soluble electron transporter for aerobic cellular respiration. Cofactor biosynthesis; ubiquinone biosynthesis. Forms homopolymers. Predominantly associated with a complex of about 500 kDa. Expressed in stems, leaves, buds and flowers. Strongly induced by UV-B. Belongs to the protein kinase superfamily. ADCK protein kinase family.