COQ9 is an enzyme that is required for the biosynthesis of coenzyme Q [1]. It may either catalyse a reaction in the coenzyme Q biosynthetic pathway or have a regulatory role.

1: COQ9, a new gene required for the biosynthesis of coenzyme Q in Saccharomyces cerevisiae. Johnson A, Gin P, Marbois BN, Hsieh EJ, Wu M, Barros MH, Clarke CF, Tzagoloff A; J Biol Chem 2005; [Epub ahead of print] PMID:16027161