IUBMB Enzyme Nomenclature


Accepted name: geranylhydroquinone 3''-hydroxylase

Reaction: geranylhydroquinone + [reduced NADPH—hemoprotein reductase] + O2 = 3''-hydroxygeranylhydroquinone + [oxidized NADPH—hemoprotein reductase] + H2O

Glossary: 3''-hydroxygeranylhydroquinone = 2-[(2Z)-3-(hydroxymethyl)-7-methylocta-2,6-dien-1-yl]benzene-1,4-diol

Other name(s): GHQ 3''-hydroxylase; CYP76B74 (gene name); geranylhydroquinone,NADPH:oxygen oxidoreductase (3''-hydroxylating)

Systematic name: geranylhydroquinone,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (3''-hydroxylating)

Comments: A cytochrome P-450 (heme-thiolate) protein found in plants, where it is part of the biosynthesis pathway of the red naphthoquinone pigment shikonin.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Yamamoto, H., Inoue, K., Li, S.M. and Heide, L. Geranylhydroquinone 3''-hydroxylase, a cytochrome P-450 monooxygenase from Lithospermum erythrorhizon cell suspension cultures. Planta 210 (2000) 312-317. [PMID: 10664138]

2. Wang, S., Wang, R., Liu, T., Lv, C., Liang, J., Kang, C., Zhou, L., Guo, J., Cui, G., Zhang, Y., Werck-Reichhart, D., Guo, L. and Huang, L. CYP76B74 catalyzes the 3''-hydroxylation of geranylhydroquinone in shikonin biosynthesis. Plant Physiol. 179 (2019) 402-414. [PMID: 30498024]

[EC created 2010 as EC, transferred 2020 to EC]

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