Protein
Ubiquinone biosynthesis monooxygenase COQ6, mitochondrial
Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Function
FAD-dependent monooxygenase required for the C5-ring hydroxylation during ubiquinone biosynthesis. Catalyzes the hydroxylation of 3-hexaprenyl-4-hydroxybenzoic acid (HHB) to 3-hexaprenyl-4,5-dihydroxybenzoic acid (DHHB). The electrons required for the hydroxylation reaction may be funneled indirectly from NADPH via ferredoxin (YAH1) and ferredoxin reductase (ARH1) to COQ6 (By similarity) (PubMed:21944752). Can also convert 3-hexaprenyl-4-aminobenzoic acid (HAB), a COQ2-prenylated pABA, to DHHB in a too step process. HAB is first hydroxylated at C5 to yield 3-hexaprenyl-4-amino-5-hydroxybenzoic acid (HHAB) which is further deaminated at C4 by COQ6 to produce DHHB (PubMed:26260787).
Similarity
Belongs to the UbiH/COQ6 family.
Sequence
MFFSKVMLTRRILVRGLATAKSSAPKLTDVLIVGGGPAGLTLAASIKNSPQLKDLKTTLVDMVDLKDKLSDFYNSPPDYFTNRIVSVTPRSIHFLENNAGATLMHDRIQSYDGLYVTDGCSKATLDLARDSMLCMIEIINIQASLYNRISQYDSKKDSIDIIDNTKVVNIKHSDPNDPLSWPLVTLSNGEVYKTRLLVGADGFNSPTRRFSQIPSRGWMYNAYGVVASMKLEYPPFKLRGWQRFLPTGPIAHLPMPENNATLVWSSSERLSRLLLSLPPESFTALINAAFVLEDADMNYYYRTLEDGSMDTDKLIEDIKFRTEEIYATLKDESDIDEIYPPRVVSIIDKTRARFPLKLTHADRYCTDRVALVGDAAHTTHPLAGQGLNMGQTDVHGLVYALEKAMERGLDIGSSLSLEPFWAERYPSNNVLLGMADKLFKLYHTNFPPVVALRTFGLNLTNKIGPVKNMIIDTLGGNEK