In enzymology, an estradiol 17beta-dehydrogenase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are estradiol and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>). Its products are estrone, reduced NADH, and a proton. The enzyme can alternatively use nicotinamide adenine dinucleotide phosphate as its cofactor.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is estradiol-17beta:NAD(P)<sup>+</sup> 17-oxidoreductase. Other names in common use include 20alpha-hydroxysteroid dehydrogenase, 17beta,20alpha-hydroxysteroid dehydrogenase, 17beta-estradiol dehydrogenase, estradiol dehydrogenase, estrogen 17-oxidoreductase, and 17beta-HSD. This enzyme participates in androgen and estrogen metabolism.
As of late 2007, 29 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , , , , , , , , , and .