View source for 3alpha(17beta)-hydroxysteroid dehydrogenase (NAD+)

{{enzyme
| Name = 3beta-hydroxy-5beta-steroid dehydrogenase
| EC_number = 1.1.1.277
| CAS_number = 
| IUBMB_EC_number = 1/1/1/277
| GO_code = 
| image = 
| width = 
| caption = 
}}
In [[enzymology]], a '''3beta-hydroxy-5beta-steroid dehydrogenase''' ({{EC number|1.1.1.277}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:3beta-hydroxy-5beta-pregnane-20-one + NADP<sup>+</sup> <math>\rightleftharpoons</math> 5beta-pregnan-3,20-dione + NADPH + H<sup>+</sup>

Thus, the two [[substrate (biochemistry)|substrates]] of this enzyme are [[3beta-hydroxy-5beta-pregnane-20-one]] and [[nicotinamide adenine dinucleotide phosphate|NADP<sup>+</sup>]], whereas its 3 [[product (chemistry)|products]] are [[5beta-pregnan-3,20-dione]], [[nicotinamide adenine dinucleotide phosphate|NADPH]], and [[hydrogen ion|H<sup>+</sup>]].

This enzyme belongs to the family of [[oxidoreductase]]s, 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 '''3beta-hydroxy-5beta-steroid:NADP<sup>+</sup> 3-oxidoreductase'''. Other names in common use include '''3beta-hydroxysteroid 5beta-oxidoreductase''', and '''3beta-hydroxysteroid 5beta-progesterone oxidoreductase'''.

==References==
{{reflist|1}}
* {{cite journal | author = Stuhlemmer U and Kreis W | date = 1996 | title = Cardenolide formation and activity of pregnane-modifying enzymes in cell suspension cultures, shoot cultures and leaves of ''Digitalis lanata'' | journal = Plant Physiol. | volume = 34 | pages = 85&ndash;91 }}
* {{cite journal | author = Seitz HU and Gaertner DE | date = 1994 | title = Enzymes in cardenolide-accumulating shoot cultures of ''Digitalis purpurea'' | journal = Plant Cell | volume = 38 | pages = 337&ndash;344 }}
* {{cite journal | author = Lindemann P and Luckner M | date = 1997 | title = Biosynthesis of pregnane derivatives in somatic embryos of ''Digitalis lanata'' | journal = [[Phytochemistry (journal)|Phytochemistry]] | volume = 46 | pages = 507&ndash;513 | doi = 10.1016/S0031-9422(97)00315-4 | issue = 3 }}

[[Category:EC 1.1.1]]
[[Category:NADPH-dependent enzymes]]
[[Category:Enzymes of unknown structure]]

{{1.1.1-enzyme-stub}}