Reaction: 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione + FMNH2 + O2 = 3,4-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione + FMN + H2O
Other name(s): HsaA
Systematic name: 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione,FMNH2:oxygen oxidoreductase
Comments: This bacterial enzyme participates in the degradation of several steroids, including cholesterol and testosterone. It can use either FADH or FMNH2 as flavin cofactor. The enzyme forms a two-component system with a reductase (HsaB) that utilizes NADH to reduce the flavin, which is then transferred to the oxygenase subunit.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, UM-BBD, CAS registry number:
1. Dresen, C., Lin, L.Y., D'Angelo, I., Tocheva, E.I., Strynadka, N. and Eltis, L.D. A flavin-dependent monooxygenase from Mycobacterium tuberculosis involved in cholesterol catabolism. J. Biol. Chem. 285 (2010) 22264-22275. [PMID: 20448045]