Reaction: A 3-oxo-Δ5-steroid = a 3-oxo-Δ4-steroid
For diagram click here.
Other name(s): hydroxysteroid isomerase; steroid isomerase; Δ5-ketosteroid isomerase; Δ5(or Δ4)-3-keto steroid isomerase; Δ5-steroid isomerase; 3-oxosteroid isomerase; Δ5-3-keto steroid isomerase; Δ5-3-oxosteroid isomerase
Systematic name: 3-oxosteroid Δ5-Δ4-isomerase
Comments: This activity is catalysed by several distinct enzymes (cf. EC 1.1.3.6, cholesterol oxidase and EC 1.1.1.145, 3-hydroxy-5-steroid dehydrogenase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9031-36-1
References:
1. Ewald, W., Werbein, H. and Chaikoff, I.L. Evidence for the presence of 17-hydroxypregnenedione isomerase in beef adrenal cortex. Biochim. Biophys. Acta 111 (1965) 306-312. [PMID: 5867327]
2. Kawahara, F.S. and Talalay, P. Crystalline Δ5-3-ketosteroid isomerase. J. Biol. Chem. 235 (1960) PC1-PC2.
3. Talalay, P. and Wang, V.S. Enzymic isomerization of Δ5-3-ketosteroids. Biochim. Biophys. Acta 18 (1955) 300-301.