Aldo-keto reductase family 1 member D1 (EC 1.3.1.3) (3-oxo-5-beta-steroid 4-dehydrogenase) (Delta(4)-3-ketosteroid 5-beta-reductase) (Delta(4)-3-oxosteroid 5-beta-reductase)
1_MDLSA 6_ ASHRI 11_ PLSDG 16_ NSIPI 21_ IGLGT 26_ YSEPK 31_ STPKG 36_ ACATS 41_ VKVAI 46_ DTGYR 51_ HIDGA 56_ YIYQN 61_ EHEVG 66_ EAIRE 71_ KIAEG 76_ KVRRE 81_ DIFYC 86_ GKLWA 91_ TNHVP 96_ EMVRP 101_ TLERT 106_ LRVLQ 111_ LDYVD 116_ LYIIE 121_ VPMAF 126_ KPGDE 131_ IYPRD 136_ ENGKW 141_ LYHKS 146_ NLCAT 151_ WEAME 156_ ACKDA 161_ GLVKS 166_ LGVSN 171_ FNRRQ 176_ LELIL 181_ NKPGL 186_ KHKPV 191_ SNQVE 196_ CHPYF 201_ TQPKL 206_ LKFCQ 211_ QHDIV 216_ ITAYS 221_ PLGTS 226_ RNPIW 231_ VNVSS 236_ PPLLK 241_ DALLN 246_ SLGKR 251_ YNKTA 256_ AQIVL 261_ RFNIQ 266_ RGVVV 271_ IPKSF 276_ NLERI 281_ KENFQ 286_ IFDFS 291_ LTEEE 296_ MKDIE 301_ ALNKN 306_ VRFVE 311_ LLMWR 316_ DHPEY 321_PFHDE
1: Catalyzes the stereospecific NADPH-dependent reduction of the C4-C5 double bond of bile acid intermediates and steroid hormones carrying a delta(4)-3-one structure to yield an A/B cis-ring junction. This cis-configuration is crucial for bile acid biosynthesis and plays important roles in steroid metabolism. Capable of reducing a broad range of delta-(4)-3-ketosteroids from C18 (such as, 17beta-hydroxyestr-4-en-3-one) to C27 (such as, 7alpha-hydroxycholest-4-en-3-one)