MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

Digitalis lanata: NADPH:3α-hydroxysteroid 5α-oxidoreductaseInferred from experiment
Homo sapiens: 3α hydroxysteroid dehydrogenase III: AKR1C2
Aldo-keto reductase family 1 member C1: AKR1C1
Aldo-keto reductase family 1 member C3: AKR1C3
Aldo-keto reductase family 1 member C4: AKR1C4

In Pathway: cardenolide biosynthesis

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the Enzyme Commission system.

Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Direct generic reaction:
allopregnanolone + NAD(P)+ ↔ 5-α-pregnane-3,20-dione + NAD(P)H + H+ (

Enzyme Commission Primary Name: 3β-hydroxy-5α-steroid dehydrogenase

Standard Gibbs Free Energy (ΔrG in kcal/mol): -1.6264954Inferred by computational analysis [Latendresse13]

Citations: [Warneck]

Gene-Reaction Schematic

Gene-Reaction Schematic

Instance reactions of [testosterone + NAD(P)+ → androst-4-ene-3,17-dione + NAD(P)H + H+] (
i3: testosterone + NAD+ = androst-4-ene-3,17-dione + NADH + H+ (

i4: testosterone + NADP+ ← androst-4-ene-3,17-dione + NADPH + H+ (

Instance reactions of [allopregnanolone + NAD(P)+ ↔ 5-α-pregnane-3,20-dione + NAD(P)H + H+] (
i1: allopregnanolone + NAD+ → 5-α-pregnane-3,20-dione + NADH + H+ (1.1.-.-)

i2: allopregnanolone + NADP+ ← 5-α-pregnane-3,20-dione + NADPH + H+ (

Unification Links: KEGG:R07138, Rhea:18137

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Warneck: Warneck HM, Seitz HU "3 beta-hydroxysteroid oxidoreductase in suspension cultures of Digitalis lanata EHRH." Z Naturforsch C 45(9-10);963-72. PMID: 2291772

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Tue Nov 24, 2015, biocyc11.