Hydroxysteroid dehydrogenase

Class of oxidoreductase enzymes

Hydroxysteroid dehydrogenases (HSDs) are a group of alcohol oxidoreductases that catalyze the dehydrogenation of hydroxysteroids. These enzymes also catalyze the reverse reaction, acting as ketosteroid reductases (KSRs).

There are four types, classified by the number of the position acted upon:

Carbon	Hydroxysteroid	Ketosteroid
3α-HSD	3α-Androstanediol	Dihydrotestosterone
3α-HSD	3α-Etiocholanediol	5β-Dihydrotestosterone
3β-HSD	Pregnenolone	Progesterone
3β-HSD	17α-Hydroxypregnenolone	17α-Hydroxyprogesterone
3β-HSD	Dehydroepiandrosterone	Androstenedione
3β-HSD	Androstenediol	Testosterone
11β-HSD	Cortisol	Cortisone
17β-HSD	Androstenedione	Testosterone
17β-HSD	Androstanedione	Dihydrotestosterone
17β-HSD	Estrone	Estradiol
20β-HSD	Progesterone	20α-Dihydroprogesterone

External links

Hydroxysteroid+Dehydrogenases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

Metabolism: lipid metabolism – ketones/cholesterol synthesis enzymes/steroid metabolism

Mevalonate pathway

To HMG-CoA	Acetyl-Coenzyme A acetyltransferase HMG-CoA synthase (regulated step)
Ketogenesis	HMG-CoA lyase 3-hydroxybutyrate dehydrogenase Thiophorase
To Mevalonic acid	HMG-CoA reductase
To DMAPP	Mevalonate kinase Phosphomevalonate kinase Pyrophosphomevalonate decarboxylase Isopentenyl-diphosphate delta isomerase
Geranyl-	Dimethylallyltranstransferase Geranyl pyrophosphate

To cholesterol

To lanosterol	Farnesyl-diphosphate farnesyltransferase Squalene monooxygenase Lanosterol synthase
7-Dehydrocholesterol path	Lanosterol 14α-demethylase Sterol-C5-desaturase-like 7-Dehydrocholesterol reductase
Desmosterol path	24-Dehydrocholesterol reductase

To Bile acids

Steroidogenesis

To pregnenolone

Cholesterol side-chain cleavage

To corticosteroids

aldosterone: 18-Hydroxylase

cortisol/cortisone: 17α-Hydroxylase
11β-HSD
- 1
- 2

both: 3β-HSD
- 1
- 2
21-Hydroxylase
11β-Hydroxylase

To sex hormones

To androgens	17α-Hydroxylase 17,20-Lyase 3β-HSD 17β-HSD 5α-Reductase 1 2
To estrogens	Aromatase 17β-HSD

Other/ungrouped

v t e Oxidoreductases: alcohol oxidoreductases (EC 1.1)
1.1.1: NAD/NADP acceptor	3-hydroxyacyl-CoA dehydrogenase 3-hydroxybutyryl-CoA dehydrogenase Alcohol dehydrogenase Aldo-keto reductase 1A1 1B1 1B10 1C1 1C3 1C4 7A2 Aldose reductase Beta-Ketoacyl ACP reductase Carbohydrate dehydrogenases Carnitine dehydrogenase D-malate dehydrogenase (decarboxylating) DXP reductoisomerase Glucose-6-phosphate dehydrogenase Glycerol-3-phosphate dehydrogenase HMG-CoA reductase IMP dehydrogenase Isocitrate dehydrogenase Lactate dehydrogenase L-threonine dehydrogenase L-xylulose reductase Malate dehydrogenase Malate dehydrogenase (decarboxylating) Malate dehydrogenase (NADP+) Malate dehydrogenase (oxaloacetate-decarboxylating) Malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) Phosphogluconate dehydrogenase Sorbitol dehydrogenase Hydroxysteroid dehydrogenase: 3β 3β-HSD NSDHL 11β 11β-HSD1 11β-HSD2 17β
1.1.2: cytochrome acceptor	D-lactate dehydrogenase (cytochrome) D-lactate dehydrogenase (cytochrome c-553) Mannitol dehydrogenase (cytochrome)
1.1.3: oxygen acceptor	Glucose oxidase L-gulonolactone oxidase Xanthine oxidase Alcohol oxidase
1.1.4: disulfide as acceptor	Vitamin K epoxide reductase Vitamin-K-epoxide reductase (warfarin-insensitive)
1.1.5: quinone/similar acceptor	Malate dehydrogenase (quinone) Quinoprotein glucose dehydrogenase
1.1.99: other acceptors	Choline dehydrogenase L2HGDH

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)