ID 1.1.1.209 DE 3(or 17)alpha-hydroxysteroid dehydrogenase. CA (1) androsterone + NADP(+) = 5alpha-androstan-3,17-dione + NADPH + H(+). CA (2) androsterone + NAD(+) = 5alpha-androstan-3,17-dione + NADH + H(+). CC -!- Acts on the 3alpha-hydroxy group of androgens of the 5alpha- CC androstane series; and also, more slowly, on the 17alpha-hydroxyl CC group of both androgenic and estrogenic substrates (cf. EC 1.1.1.51). DR Q04828, AK1C1_HUMAN; Q95JH7, AK1C1_MACFA; Q95JH6, AK1C1_MACFU; DR Q5REQ0, AK1C1_PONAB; P52895, AK1C2_HUMAN; P52898, AK1C4_BOVIN; DR P17516, AK1C4_HUMAN; Q95JH5, AK1C4_MACFA; Q95JH4, AK1C4_MACFU; DR Q91WR5, AK1CL_MOUSE; Q6AYQ2, AK1CL_RAT ; Q8HYR6, DHRS9_BOVIN; DR Q9BPW9, DHRS9_HUMAN; Q58NB6, DHRS9_MOUSE; Q8VD48, DHRS9_RAT ; DR Q3T001, H17B6_BOVIN; O14756, H17B6_HUMAN; Q9R092, H17B6_MOUSE; DR O54753, H17B6_RAT ; O75452, RDH16_HUMAN; O54909, RDH16_MOUSE; DR P50170, RDH16_RAT ; Q27979, RDH5_BOVIN ; Q92781, RDH5_HUMAN ; DR O55240, RDH5_MOUSE ; //