NADPH-dependent oxidoreductase which catalyzes the reduction of a variety of compounds bearing carbonyl groups including ketosteroids, alpha-dicarbonyl compounds, aldehydes, aromatic ketones and quinones (PubMed:12604222, PubMed:9880795, PubMed:19056333). Reduces all-trans-retinal and 9-cis retinal (Probable). Reduces 3-ketosteroids and benzil into 3alpha-hydroxysteroids and S-benzoin, respectively, in contrast to the stereoselectivity of primates DHRS4s which produce 3beta-hydroxysteroids and R-benzoin (By similarity). In the reverse reaction, catalyze the NADP-dependent oxidation of 3alpha-hydroxysteroids and alcohol, but with much lower efficiency (By similarity). Involved in the metabolism of 3alpha-hydroxysteroids, retinoid, isatin and xenobiotic carbonyl compounds (PubMed:12604222, PubMed:19056333). a secondary alcohol + NADP(+) = a ketone + H(+) + NADPH 3alpha-hydroxy-5beta-pregnan-20-one + NADP(+) = 5beta-pregnan-3,20-dione + H(+) + NADPH 5beta-dihydrotestosterone + H(+) + NADPH = 5beta-androstane-3alpha,17beta-diol + NADP(+) all-trans-retinol + NADP(+) = all-trans-retinal + H(+) + NADPH H(+) + isatin + NADPH = 3-hydroxyindolin-2-one + NADP(+) Inhibited by flavonoids (kaempferol, quercetin, quercitrin, genistein), myristic acid, pyrazole, barbital, phenobarbital and CuSO4. kcat is 2 min(-1) with 5beta-Pregnane-3,20-dione as substrate (at pH7.4). Homotetramer. Detected in liver and kidney. Detected at lower levels in heart, lung, spleen, small intestine, testis, brain and stomach. The C-terminus peroxisomal targeting signal tripeptide is important for peroxisomal import. Once in the peroxisome, it is involved in intersubunit interactions. Three specific residues, Phe-158, Leu-161 and Asn-177 are conserved between non-primate mammals whereas the respective residues are serine, phenylalanine and threonine in primates (PubMed:19056333). The two residues at positions 158 and 161 are molecular determinants responsible for the stereoselective reduction of 3-ketosteroids and benzil (PubMed:19056333). The presence of an asparagine at position 177 is important for the maintenance of the quaternary structure resulting in stability at cold temperature and improved catalytic activity toward retinal (PubMed:19056333). Primate DHRS4s display different stereoselectivity and catalytic efficiency in the oxidoreduction of some substrates as compared to other mammal DHRS4s due to a difference in conserved amino acid residues. Belongs to the short-chain dehydrogenases/reductases (SDR) family.