Enzymes
| UniProtKB help_outline | 7 proteins |
| Enzyme class help_outline |
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- Name help_outline cholest-5-en-3-one Identifier CHEBI:63906 (CAS: 601-54-7) help_outline Charge 0 Formula C27H44O InChIKeyhelp_outline GGCLNOIGPMGLDB-GYKMGIIDSA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])[C@]3([H])CC=C4CC(=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 cholest-4-en-3-one Identifier CHEBI:16175 (CAS: 601-57-0) help_outline Charge 0 Formula C27H44O InChIKeyhelp_outline NYOXRYYXRWJDKP-GYKMGIIDSA-N SMILEShelp_outline [H][C@@]1(CC[C@@]2([H])[C@]3([H])CCC4=CC(=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 9 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:32187 | RHEA:32188 | RHEA:32189 | RHEA:32190 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Related reactions help_outline
More general form(s) of this reaction
Publications
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Cholesterol oxidase: biochemistry and structural features.
Vrielink A., Ghisla S.
Cholesterol oxidases are bifunctional flavoenzymes that catalyze the oxidation of steroid substrates which have a hydroxyl group at the 3beta position of the steroid ring system. The enzyme is found, in a wide range of bacterial species, in two forms: one with the FAD cofactor bound noncovalently ... >> More
Cholesterol oxidases are bifunctional flavoenzymes that catalyze the oxidation of steroid substrates which have a hydroxyl group at the 3beta position of the steroid ring system. The enzyme is found, in a wide range of bacterial species, in two forms: one with the FAD cofactor bound noncovalently to the enzyme; and one with the cofactor linked covalently to the protein. Here we discuss, compare and contrast the salient biochemical properties of the two forms of the enzyme. Specifically, the structural features are discussed that affect the redox potentials of the flavin cofactor, the chemical mechanism of substrate dehydrogenation by active-center amino acid residues, the kinetic parameters of both types of enzymes and the reactivity of reduced enzymes with molecular dioxygen. The presence of a molecular tunnel that is proposed to serve in the access of dioxygen to the active site and mechanisms of its control by a 'gate' formed by amino acid residues are highlighted. << Less
FEBS J 276:6826-6843(2009) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Rv1106c from Mycobacterium tuberculosis is a 3beta-hydroxysteroid dehydrogenase.
Yang X., Dubnau E., Smith I., Sampson N.S.
New approaches are required to combat Mycobacterium tuberculosis (Mtb), especially the multi-drug resistant and extremely drug resistant organisms (MDR-TB and XDR-TB). There are many reports that mycobacteria oxidize 3beta-hydroxysterols to 3-ketosteroids, but the enzymes responsible for this acti ... >> More
New approaches are required to combat Mycobacterium tuberculosis (Mtb), especially the multi-drug resistant and extremely drug resistant organisms (MDR-TB and XDR-TB). There are many reports that mycobacteria oxidize 3beta-hydroxysterols to 3-ketosteroids, but the enzymes responsible for this activity have not been identified in mycobacterial species. In this work, the Rv1106c gene that is annotated as a 3beta-hydroxysteroid dehydrogenase in Mtb has been cloned and heterologously expressed. The purified enzyme was kinetically characterized and found to have a pH optimum between 8.5 and 9.5. The enzyme, which is a member of the short chain dehydrogenase superfamily, uses NAD+ as a cofactor and oxidizes cholesterol, pregnenolone, and dehydroepiandrosterone to their respective 3-keto-4-ene products. The enzyme forms a ternary complex with NAD+ binding before the sterol. The enzyme shows no substrate preference for dehydroepiandrosterone versus pregnenolone with second-order rate constants (kcat/Km) of 3.2 +/- 0.4 and 3.9 +/-0.9 microM-1 min-1, respectively, at pH 8.5, 150 mM NaCl, 30 mM MgCl2, and saturating NAD+. Trilostane is a competitive inhibitor of dehydroepiandrosterone with a Ki of 197 +/-8 microM. The expression of the 3beta-hydroxysteroid dehydrogenase in Mtb is intracellular. Disruption of the 3beta-hydroxysteroid dehydrogenase gene in Mtb abrogates mycobacterial cholesterol oxidation activity. These data are consistent with the Rv1106c gene being the one responsible for 3beta-hydroxysterol oxidation in Mtb. << Less
Biochemistry 46:9058-9067(2007) [PubMed] [EuropePMC]
This publication is cited by 7 other entries.
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Cholesterol oxidase: structure and function.
Vrielink A.
Cholesterol oxidase is a bacterial-specific flavoenzyme that catalyzes the oxidation and isomerisation of steroids containing a 3beta hydroxyl group and a double bond at the Delta5-6 of the steroid ring system. The enzyme is a member of a large family of flavin-specific oxidoreductases and is foun ... >> More
Cholesterol oxidase is a bacterial-specific flavoenzyme that catalyzes the oxidation and isomerisation of steroids containing a 3beta hydroxyl group and a double bond at the Delta5-6 of the steroid ring system. The enzyme is a member of a large family of flavin-specific oxidoreductases and is found in two different forms: one where the flavin adenine dinucleotide (FAD) cofactor is covalently linked to the protein and one where the cofactor is non-covalently bound to the protein. These two enzyme forms have been extensively studied in order to gain insight into the mechanism of flavin-mediated oxidation and the relationship between protein structure and enzyme redox potential. More recently the enzyme has been found to play an important role in bacterial pathogenesis and hence further studies are focused on its potential use for future development of novel antibacterial therapeutic agents. In this review the biochemical, structural, kinetic and mechanistic features of the enzyme are discussed. << Less
Subcell Biochem 51:137-158(2010) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.