Steroid Delta-isomerase

a 3-oxo-Delta₅-steroid $rightleftharpoons$ a 3-oxo-Delta₄-steroid

Hence, this enzyme has one substrate, 3-oxo-Delta5-steroid, and one product, 3-oxo-Delta4-steroid.

This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases transposing C=C bonds. The systematic name of this enzyme class is 3-oxosteroid Delta5-Delta4-isomerase. Other names in common use include hydroxysteroid isomerase, steroid isomerase, Delta5-ketosteroid isomerase, Delta5(or Delta4)-3-keto steroid isomerase, Delta5-steroid isomerase, 3-oxosteroid isomerase, Delta5-3-keto steroid isomerase, and Delta5-3-oxosteroid isomerase. This enzyme participates in c21-steroid hormone metabolism and androgen and estrogen metabolism.

Structural studies

As of late 2007, 25 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , , , , , and .

References

• Ewald W, Werbin H, Chaikoff IL "Evidence for the presence of 17-hydroxypregnenedione isomerase in beef adrenal cortex". Biochim. Biophys. Acta. 111 306–12.
• Kawahara FS and Talalay P "Crystalline Delta5-3-ketosteroid isomerase". J. Biol. Chem. 235 PC1–PC2.
• Talalay P and Wang VS "Enzymic isomerization of Delta5-3-ketosteroids". Biochim. Biophys. Acta 18 300–301.

External links

The CAS registry number for this enzyme class is .

Gene Ontology (GO) codes