MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number:

Enzymes and Genes:

Digitalis lanata : NADPH:3α-hydroxysteroid 5α-oxidoreductase Inferred 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 reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. 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): -1.6264954 Inferred 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 SRI International Pathway Tools version 19.0 on Sun Oct 4, 2015, BIOCYC14A.