title: [Enzymes involved in modification of the steroid nucleus of industrial mycobacterial strains: isolation, functions, and properties].
abstract: The key enzymes involved in modification of the steroid nucleus of sterol-transforming mycobacteria--3beta-hydroxysteroid oxidase (3-OH-SO, EC 1.13.1.2) and 17beta-hydroxysteroid dehydrogenase (17-OH-SDH, EC 1.1.1)--were isolated and characterized. It is shown that 3-OH-SO is a multifunctional enzyme catalyzing oxidation of the 3beta-OH group, delta5 --> delta4 isomerization, and 6-hydroxylation. Two forms of intracellular 17-OH-SDH that catalyze redox reactions at C17 were found, and their properties were determined. The presence of an extracellular 17-OH-SDH in Mycobacterium spp. (VKM Ac-1815 D and Et1) was demonstrated for the first time.
authors.forename: M V
authors.initials: MV
authors.lastname: Donova
authors.forename: V M
authors.initials: VM
authors.lastname: Nikolaeva
authors.forename: O V
authors.initials: OV
authors.lastname: Egorova
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000302:isolation & purification / Q000378:metabolism*; D017077:Culture Media, Conditioned / Q000378:metabolism; D006900:Hydroxylation; D006913:Hydroxysteroid Dehydrogenases / Q000302:isolation & purification / Q000378:metabolism*; D009161:Mycobacterium / Q000201:enzymology*; D010084:Oxidation-Reduction; D012855:Sitosterols; D013261:Sterols / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D012855:Sitosterols; D013261:Sterols; D013739:Testosterone; D015096:3-Hydroxysteroid Dehydrogenases; D006913:Hydroxysteroid Dehydrogenases; C035507:3(17)-hydroxysteroid dehydrogenase