Rhea - reaction knowledgebase

Enzymes

UniProtKB ^help_outline	6 proteins
Enzyme class ^help_outline	EC 1.1.1.277 3beta-hydroxy-5beta-steroid dehydrogenase
GO Molecular Function ^help_outline	GO:0033703 3beta-hydroxy-5beta-steroid dehydrogenase activity

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Name ^help_outline 3β-hydroxy-5β-pregnane-20-one Identifier CHEBI:16229 (Beilstein: 3035289; CAS: 128-21-2) ^help_outline Charge 0 Formula C21H34O2 InChIKey^help_outline AURFZBICLPNKBZ-GRWISUQFSA-N SMILES^help_outline [H][C@]12CC[C@@]3([H])[C@]4([H])CC[C@]([H])(C(C)=O)[C@@]4(C)CC[C@]3([H])[C@@]1(C)CC[C@H](O)C2 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Name ^help_outline NADP⁺ Identifier CHEBI:58349 Charge -3 Formula C21H25N7O17P3 InChIKey^help_outline XJLXINKUBYWONI-NNYOXOHSSA-K SMILES^help_outline NC(=O)c1ccc[n+](c1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,253 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Name ^help_outline 5β-pregnan-3,20-dione Identifier CHEBI:30154 (CAS: 128-23-4) ^help_outline Charge 0 Formula C21H32O2 InChIKey^help_outline XMRPGKVKISIQBV-XWOJZHJZSA-N SMILES^help_outline [H][C@]12CC[C@@]3([H])[C@]4([H])CC[C@H](C(C)=O)[C@@]4(C)CC[C@]3([H])[C@@]1(C)CCC(=O)C2 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Name ^help_outline H⁺ Identifier CHEBI:15378 Charge 1 Formula H InChIKey^help_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILES^help_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,176 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Name ^help_outline NADPH Identifier CHEBI:57783 (Beilstein: 10411862) ^help_outline Charge -4 Formula C21H26N7O17P3 InChIKey^help_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILES^help_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,247 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule

Cross-references

	RHEA:22944	RHEA:22945	RHEA:22946	RHEA:22947
Reaction direction	undefined	left-to-right	right-to-left	bidirectional
UniProtKB ^help_outline	6 proteins		6 proteins
EC numbers ^help_outline	1.1.1.277
Gene Ontology ^help_outline	GO:0033703
KEGG ^help_outline				R06166
MetaCyc ^help_outline				1.1.1.277-RXN

Publications

Human 3alpha-hydroxysteroid dehydrogenase isoforms (AKR1C1-AKR1C4) of the aldo-keto reductase superfamily: functional plasticity and tissue distribution reveals roles in the inactivation and formation of male and female sex hormones.

Penning T.M., Burczynski M.E., Jez J.M., Hung C.F., Lin H.K., Ma H., Moore M., Palackal N., Ratnam K.

The kinetic parameters, steroid substrate specificity and identities of reaction products were determined for four homogeneous recombinant human 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) isoforms of the aldo-keto reductase (AKR) superfamily. The enzymes correspond to type 1 3alpha-HSD (AKR1 ... >> More

The kinetic parameters, steroid substrate specificity and identities of reaction products were determined for four homogeneous recombinant human 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) isoforms of the aldo-keto reductase (AKR) superfamily. The enzymes correspond to type 1 3alpha-HSD (AKR1C4), type 2 3alpha(17beta)-HSD (AKR1C3), type 3 3alpha-HSD (AKR1C2) and 20alpha(3alpha)-HSD (AKR1C1), and share at least 84% amino acid sequence identity. All enzymes acted as NAD(P)(H)-dependent 3-, 17- and 20-ketosteroid reductases and as 3alpha-, 17beta- and 20alpha-hydroxysteroid oxidases. The functional plasticity of these isoforms highlights their ability to modulate the levels of active androgens, oestrogens and progestins. Salient features were that AKR1C4 was the most catalytically efficient, with k(cat)/K(m) values for substrates that exceeded those obtained with other isoforms by 10-30-fold. In the reduction direction, all isoforms inactivated 5alpha-dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-one; 5alpha-DHT) to yield 5alpha-androstane-3alpha,17beta-diol (3alpha-androstanediol). However, only AKR1C3 reduced Delta(4)-androstene-3,17-dione to produce significant amounts of testosterone. All isoforms reduced oestrone to 17beta-oestradiol, and progesterone to 20alpha-hydroxy-pregn-4-ene-3,20-dione (20alpha-hydroxyprogesterone). In the oxidation direction, only AKR1C2 converted 3alpha-androstanediol to the active hormone 5alpha-DHT. AKR1C3 and AKR1C4 oxidized testosterone to Delta(4)-androstene-3,17-dione. All isoforms oxidized 17beta-oestradiol to oestrone, and 20alpha-hydroxyprogesterone to progesterone. Discrete tissue distribution of these AKR1C enzymes was observed using isoform-specific reverse transcriptase-PCR. AKR1C4 was virtually liver-specific and its high k(cat)/K(m) allows this enzyme to form 5alpha/5beta-tetrahydrosteroids robustly. AKR1C3 was most prominent in the prostate and mammary glands. The ability of AKR1C3 to interconvert testosterone with Delta(4)-androstene-3,17-dione, but to inactivate 5alpha-DHT, is consistent with this enzyme eliminating active androgens from the prostate. In the mammary gland, AKR1C3 will convert Delta(4)-androstene-3,17-dione to testosterone (a substrate aromatizable to 17beta-oestradiol), oestrone to 17beta-oestradiol, and progesterone to 20alpha-hydroxyprogesterone, and this concerted reductive activity may yield a pro-oesterogenic state. AKR1C3 is also the dominant form in the uterus and is responsible for the synthesis of 3alpha-androstanediol which has been implicated as a parturition hormone. The major isoforms in the brain, capable of synthesizing anxiolytic steroids, are AKR1C1 and AKR1C2. These studies are in stark contrast with those in rat where only a single AKR with positional- and stereo-specificity for 3alpha-hydroxysteroids exists. << Less

Biochem. J. 351:67-77(2000) [PubMed] [EuropePMC]

This publication is cited by 15 other entries.

Comments

Published in: Stuhlemmer, U. and Kreis, W. Cardenolide formation and activity of pregnane-modifying enzymes in cell suspension cultures, shoot cultures and leaves of Digitalis lanata. Plant Physiol. Biochem., 34, (1996) 85-91. Seitz, H.U. and Gaertner, D.E. Enzymes in cardenolide-accumulating shoot cultures of Digitalis purpurea. Plant Cell Tissue Organ. Cult., 38, (1994) 337-344. Lindemann, P. and Luckner, M. Biosynthesis of pregnane derivatives in somatic embryos of Digitalis lanata. Phytochemistry, 46, (1997) 507-513.