Enzymes
| UniProtKB help_outline | 3 proteins |
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- Name help_outline 4α-methyl-5α-cholest-7-en-3β-ol Identifier CHEBI:18378 (CAS: 481-25-4) help_outline Charge 0 Formula C28H48O InChIKeyhelp_outline LMYZQUNLYGJIHI-SPONXPENSA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])C3=CC[C@@]4([H])[C@H](C)[C@@H](O)CC[C@]4(C)[C@@]3([H])CC[C@]12C)[C@H](C)CCCC(C)C 2D coordinates Mol file for the small molecule Search links Involved in 3 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 InChIKeyhelp_outline XJLXINKUBYWONI-NNYOXOHSSA-K SMILEShelp_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 1,285 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 4α-methyl-5α-cholest-7-en-3-one Identifier CHEBI:16495 (CAS: 2789-43-7) help_outline Charge 0 Formula C28H46O InChIKeyhelp_outline OWKGVPXWOHLTSL-LIUJFMQASA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])C3=CC[C@@]4([H])[C@H](C)C(=O)CC[C@]4(C)[C@@]3([H])CC[C@]12C)[C@H](C)CCCC(C)C 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 InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 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 InChIKeyhelp_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILEShelp_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 1,279 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:18409 | RHEA:18410 | RHEA:18411 | RHEA:18412 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Closing the gap: identification of human 3-ketosteroid reductase, the last unknown enzyme of mammalian cholesterol biosynthesis.
Marijanovic Z., Laubner D., Moeller G., Gege C., Husen B., Adamski J., Breitling R.
The protein encoded by the HSD17B7 gene was originally described as a prolactin receptor-associated protein and as 17beta-hydroxysteroid dehydrogenase (HSD) type 7. Its ability to synthesize 17beta-estradiol in vitro has been reported previously. However, we demonstrate that HSD17B7 is the ortholo ... >> More
The protein encoded by the HSD17B7 gene was originally described as a prolactin receptor-associated protein and as 17beta-hydroxysteroid dehydrogenase (HSD) type 7. Its ability to synthesize 17beta-estradiol in vitro has been reported previously. However, we demonstrate that HSD17B7 is the ortholog of the yeast 3-ketosteroid reductase Erg27p and converts zymosterone to zymosterol in vitro, using reduced nicotinamide adenine dinucleotide phosphate as cofactor. Expression of human and murine HSD17B7 in an Erg27p-deficient yeast strain complements the 3-ketosteroid reductase deficiency of the cells and restores growth on sterol-deficient medium. A fusion of HSD17B7 with green fluorescent protein is located in the endoplasmic reticulum, the site of postsqualene cholesterogenesis. Further critical evidence for a role of HSD17B7 in cholesterol metabolism is provided by the observation that its murine ortholog is a member of the same highly distinct embryonic synexpression group as hydroxymethyl-glutaryl-coenzyme A reductase, the rate-limiting enzyme of sterol biogenesis, and is specifically expressed in tissues that are involved in the pathogenesis of congenital cholesterol-deficiency disorders. We conclude that HSD17B7 participates in postsqualene cholesterol biosynthesis, thus completing the molecular cloning of all genes of this central metabolic pathway. In its function as the 3-ketosteroid reductase of cholesterol biosynthesis, HSD17B7 is a novel candidate for inborn errors of cholesterol metabolism. << Less
Mol. Endocrinol. 17:1715-1725(2003) [PubMed] [EuropePMC]
This publication is cited by 2 other entries.
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Solubilization and partial purification of a microsomal 3-ketosteroid reductase of cholesterol biosynthesis.
Billheimer J.T., Alcorn M., Gaylor J.L.
Arch. Biochem. Biophys. 211:430-438(1981) [PubMed] [EuropePMC]
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Investigation of the component reactions of oxidative sterol demethylation. Formation and metabolism of 3-ketosteroid intermediates.
Swindell A.C., Gaylor J.L.
J Biol Chem 243:5546-5555(1968) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Characterization of the Saccharomyces cerevisiae ERG27 gene encoding the 3-keto reductase involved in C-4 sterol demethylation.
Gachotte D., Sen S.E., Eckstein J., Barbuch R., Krieger M., Ray B.D., Bard M.
The last unidentified gene encoding an enzyme involved in ergosterol biosynthesis in Saccharomyces cerevisiae has been cloned. This gene, designated ERG27, encodes the 3-keto sterol reductase, which, in concert with the C-4 sterol methyloxidase (ERG25) and the C-3 sterol dehydrogenase (ERG26), cat ... >> More
The last unidentified gene encoding an enzyme involved in ergosterol biosynthesis in Saccharomyces cerevisiae has been cloned. This gene, designated ERG27, encodes the 3-keto sterol reductase, which, in concert with the C-4 sterol methyloxidase (ERG25) and the C-3 sterol dehydrogenase (ERG26), catalyzes the sequential removal of the two methyl groups at the sterol C-4 position. We developed a strategy to isolate a mutant deficient in converting 3-keto to 3-hydroxy-sterols. An ergosterol auxotroph unable to synthesize sterol or grow without sterol supplementation was mutagenized. Colonies were then selected that were nystatin-resistant in the presence of 3-ketoergostadiene and cholesterol. A new ergosterol auxotroph unable to grow on 3-ketosterols without the addition of cholesterol was isolated. The gene (YLR100w) was identified by complementation. Segregants containing the YLR100w disruption failed to grow on various types of 3-keto sterol substrates. Surprisingly, when erg27 was grown on cholesterol- or ergosterol-supplemented media, the endogenous compounds that accumulated were noncyclic sterol intermediates (squalene, squalene epoxide, and squalene dioxide), and there was little or no accumulation of lanosterol or 3-ketosterols. Feeding experiments in which erg27 strains were supplemented with lanosterol (an upstream intermediate of the C-4 demethylation process) and cholesterol (an end-product sterol) demonstrated accumulation of four types of 3-keto sterols identified by GC/MS and chromatographic properties: 4-methyl-zymosterone, zymosterone, 4-methyl-fecosterone, and ergosta-7,24 (28)-dien-3-one. In addition, a fifth intermediate was isolated and identified by (1)H NMR as a 4-methyl-24, 25-epoxy-cholesta-7-en-3-one. Implications of these results are discussed. << Less
Proc. Natl. Acad. Sci. U.S.A. 96:12655-12660(1999) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.