title: Microbial catabolism of sterols: focus on the enzymes that transform the sterol 3β-hydroxy-5-en into 3-keto-4-en.
abstract: An overview on the microbial sterol catabolism is described with a focus on the catabolic step of the 3β-hydroxy-5-en structure. Cholesterol oxidase transforms this structure into the corresponding 3-keto-4-en feature, and thus initiates the sterol molecule catabolism. The oxidase has been found in a large number of microorganisms, especially in Actinobacteria as species of Rhodococcus and Streptomyces. Other Actinobacteria as species of Mycobacterium and Nocardia possess NAD(P)-dependent dehydrogenase for this catabolic step. In Rhodococcus jostii, oxidation of the C26 of the sterol side chain is the initiating step. The resulting stenone or sterol-C26-oic acid is then catabolized according to two subpathways: cleavage of the sterol side chain and degradation of the steroid nucleus. Divergent items concerned with the enzymes that transform the sterol 3β-hydroxy-5-en are discussed.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kreit
mesh_terms: D039903:Actinobacteria / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D002789:Cholesterol Oxidase / Q000378:metabolism; D038181:FMN Reductase / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D012240:Rhodococcus / Q000201:enzymology / Q000378:metabolism; D013261:Sterols / Q000737:chemistry / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology / Q000378:metabolism
chemical_list: D013261:Sterols; D002784:Cholesterol; D002789:Cholesterol Oxidase; D038181:FMN Reductase; D010100:Oxygen
keywords: 3β-hydroxysteroid dehydrogenase; Mycobacterium; Nocardia; Rhodococcus; cholesterol oxidase; sterol catabolism