Aerobic catabolism of sterols by microorganisms: key enzymes that open the 3-ketosteroid nucleus
| Autor: | Joseph Kreit |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Reductase
Microbiology Gene Expression Regulation Enzymologic Substrate Specificity 03 medical and health sciences chemistry.chemical_compound Oxidoreductase Ketosteroid polycyclic compounds Genetics Molecular Biology 030304 developmental biology chemistry.chemical_classification Microbiological Phenomena 0303 health sciences biology 030306 microbiology Catabolism Active site Monooxygenase Ketosteroids Lipid Metabolism Sterol Aerobiosis Sterols Enzyme chemistry Biochemistry biology.protein Oxidoreductases Oxidation-Reduction Metabolic Networks and Pathways |
| Zdroj: | FEMS microbiology letters. 366(14) |
| ISSN: | 1574-6968 |
| Popis: | Aerobic degradation of the sterol tetracyclic nucleus by microorganisms comprises the catabolism of A/B-rings, followed by that of C/D-rings. B-ring rupture at the C9,10-position is a key step involving 3-ketosteroid Δ1-dehydrogenase (KstD) and 3-ketosteroid 9α-hydroxylase (KstH). Their activities lead to the aromatization of C4,5-en-containing A-ring causing the rupture of B-ring. C4,5α-hydrogenated 3-ketosteroid could be produced by the growing microorganism containing a 5α-reductase. In this case, the microorganism synthesizes, in addition to KstD and KstH, a 3-ketosteroid Δ4-(5α)-dehydrogenase (Kst4D) in order to produce the A-ring aromatization, and consequently B-ring rupture. KstD and Kst4D are FAD-dependent oxidoreductases. KstH is composed of a reductase and a monooxygenase. This last component is the catalytic unit; it contains a Rieske-[2Fe-2S] center with a non-haem mononuclear iron in the active site. Published data regarding these enzymes are reviewed. |
| Databáze: | OpenAIRE |
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