Any feedback?
No. of entries
Information on EC 1.14.14.174 - geranylhydroquinone 3''-hydroxylase
for references in articles please use BRENDA:EC1.14.14.174
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
EC Tree 1 Oxidoreductases
1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen
1.14.14 With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor
1.14.14.174 geranylhydroquinone 3''-hydroxylase
IUBMB 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.
The enzyme appears in viruses and cellular organisms
- 1.14.14.174
- shikonin
- naphthoquinone
-
arnebia
- euchroma
- erythrorhizon
-
lithospermum
-
hairy
- pigments
Reaction Schemes
showSynonyms
cyp76b74, geranylhydroquinone 3''-hydroxylase, more
topPlease wait a moment until the data is sorted. This message will disappear when the data is sorted.
SYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
CYP76B74
EC 1.14.13.116
-
-
formerly
-
geranylhydroquinone,NADPH:oxygen oxidoreductase (3''-hydroxylating)
-
-
-
-
GHQ 3''-hydroxylase
CYP76B74
-
-
-
-
GHQ 3''-hydroxylase
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2 = 3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
PATHWAY SOURCE
PATHWAYS
MetaCyc
shikonin biosynthesis
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SYSTEMATIC NAME
IUBMB Comments
geranylhydroquinone,[reduced NADPH-hemoprotein reductase]:oxygen oxidoreductase (3''-hydroxylating)
A cytochrome P-450 (heme-thiolate) protein found in plants, where it is part of the biosynthesis pathway of the red naphthoquinone pigment shikonin.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + 2 O2
3''-carboxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: three-step oxidation of GHQ to form GHQ-3''-COOH
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: -
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
-
Substrates: likely to be involved in shikonin and dihydroechinofuran biosynthesis
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
-
Substrates: hydroxylation takes place specifically at position 3'', i.e. at the methyl group involved in the cyclization reaction. The reaction velocity obtained with 3-geranyl-4-hydroxybenzoic acid is more than 100 times lower than that obtained with geranylhydro-quinone
Products: proton/proton correlation spectroscopic and proton/proton long-range correlation spectroscopic studies confirm that hydroxylation takes place specifically at position 3''
Products: proton/proton correlation spectroscopic and proton/proton long-range correlation spectroscopic studies confirm that hydroxylation takes place specifically at position 3''
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: -
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: 3''-hydroxylation of GHQ to form GHQ-3''-OH
Products: -
Products: -
?
additional information
?
-
Substrates: reaction product analysis by HPLC, LC-MS and NMR
Products: -
Products: -
?
additional information
?
-
Substrates: reaction product analysis by HPLC, LC-MS and NMR
Products: -
Products: -
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
LITERATURE
COMMENTARY
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: -
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
-
Substrates: likely to be involved in shikonin and dihydroechinofuran biosynthesis
Products: -
Products: -
?
geranylhydroquinone + [reduced NADPH-hemoprotein reductase] + O2
3''-hydroxygeranylhydroquinone + [oxidized NADPH-hemoprotein reductase] + H2O
Substrates: -
Products: -
Products: -
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
NADPH
-
required, could not be replaced by NADH, FAD or FMN. The optimal concentration of NADPH for this reaction is between 1 and 5 mM
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7.4
-
activity in K-phosphate buffer at pH 7.4 is only 40% of that observed in Tris-HCl buffer
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
6.7 - 8.3
-
50% of maximal activiyt at pH 6.7 and pH 8.3. Tris-Cl buffer
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
30
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
additional information
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
protein is anchored to the endoplasmic reticulum membrane
brenda
Highest Expressing Human Cell Lines
Cell Line LinksPlease wait a moment until the data is sorted. This message will disappear when the data is sorted.
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
phylogenetic analysis, analysis of the evolutionary relationship among the CYP76B100, CYP76B101 and CYP76 family
metabolism
physiological function
metabolism
shikonin is derived from 4-hydroxybenzoic acid and geranyl diphosphate, originating from the shikimate pathway and mevalonate pathway, respectively. The coupling of two key precursors is catalyzed by geranyl diphosphate:4-hydroxybenzoate 3-geranyltransferase (PGT) to yield the important intermediate GBA, which is subsequently converted to geranylhydroquinone (GHQ) by a cytochrome P450 monooxygenase (CYP), CYP76B74, identified from Lithospermum erythrorhizon suspension cultures. Proposed biosynthetic pathway of shikonin in Lithospermum erythrorhizon, overview. CYP76B100 catalyzes the hydroxylation of the geranyl side-chain of GHQ at the C-3' position to form 3''-hydroxyl geranylhydroquinone (GHQ-3''-OH). The enzyme CYP76B101 carries out oxidation reaction of GHQ at the C-3'' position to produce a 3''-carboxylic acid derivative of GHQ (GHQ-3''-COOH) as well as GHQ-3''-OH
metabolism
shikonin is derived from 4-hydroxybenzoic acid and geranyl diphosphate, originating from the shikimate pathway and mevalonate pathway, respectively. The coupling of two key precursors is catalyzed by geranyl diphosphate:4-hydroxybenzoate 3-geranyltransferase (PGT) to yield the important intermediate GBA, which is subsequently converted to geranylhydroquinone (GHQ) by a cytochrome P450 monooxygenase (CYP), CYP76B74, identified from Lithospermum erythrorhizon suspension cultures. Proposed biosynthetic pathway of shikonin in Lithospermum erythrorhizon, overview. CYP76B100 catalyzes the hydroxylation of the geranyl side-chain of GHQ at the C-3'' position to form 3''-hydroxyl geranylhydroquinone (GHQ-3''-OH). The enzyme CYP76B101 carries out oxidation reaction of GHQ at the C-3'' position to produce a 3''-carboxylic acid derivative of GHQ (GHQ-3''-COOH) as well as GHQ-3''-OH
physiological function
In CYP76B74 RNA interference hairy roots, shikonin derivative accumulation decreases dramatically. CYP76B74 belongs to the CYP76B subfamily and catalyzes the key hydroxylation step in shikonin biosynthesis with high efficiency
physiological function
enzyme CYP76B100 catalyzes the C-3'' hydroxylation of GHQ to form a key intermediate 3''-hydroxy-geranylhydroquinone (GHQ-3''-OH). CYP76B100 plays an important role in the shikonin biosynthesis
physiological function
enzyme CYP76B101 catalyzes the C-3'' hydroxylation of GHQ to form a key intermediate 3''-hydroxy-geranylhydroquinone (GHQ-3''-OH). CYP76B101 plays an important role in the shikonin biosynthesis
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
UNIPROT
ENTRY NAME
ORGANISM
NO. OF AA
NO. OF TRANSM. HELICES
MOLECULAR WEIGHT[Da]
SOURCE
SEQUENCE
LOCALIZATION PREDICTION
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable).
The reliability class of the localization prediction ranges from 1 (very reliable) to 5 (not reliable). Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
addition of glycerol (20%, v/v) to the microsomal fraction before freezing results in the loss of 80% of the activity
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-70°C, 1 month, microsomal protein retains 82% of the original activity
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
partially, microsome preparation of recombinant enzyme expressed from Saccharomyces cerevisiae strain BY4742
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
gene CYP76B100, DNA and amino acid sequence determination and analysis, phylogenetic analysis, recombinant expression in Saccharomyces cerevisiae strain BY4742
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Yamamoto. H.; Inoue, K.; Li, S.M.; Heide, L.
Geranylhydroquinone 3"-hydroxylase, a cytochrome P-450 monooxygenase from Lithospermum erythrorhizon cell suspension cultures
Planta
210
312-317
2000
Lithospermum erythrorhizon
brenda
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.; Huang, L.
CYP76B74 catalyzes the 3''-hydroxylation of geranylhydroquinone in shikonin biosynthesis
Plant Physiol.
179
402-414
2019
Arnebia euchroma (A0A3Q9R4N5), Arnebia euchroma
brenda
Song, W.; Zhuang, Y.; Liu, T.
Potential role of two cytochrome P450s obtained from Lithospermum erythrorhizon in catalyzing the oxidation of geranylhydroquinone during shikonin biosynthesis
Phytochemistry
75
112375
2020
Lithospermum erythrorhizon (A0A6M3TXH1), Lithospermum erythrorhizon (A0A6M3TY96)
brenda
EXTERNAL LINKS (specific for EC-Number 1.14.14.174)
html completed
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2026.1 (March 2026)
About BRENDA
Social media
Help
Survey
Download
Contribution
Legal
Curated at
Member of
![DSMZ Digital Diversity]()
![Global Core Biodata Resource]()
![ELIXIR Core Data Resource]()
![German Network for Bioinformatics Infrastructure]()
