This domain is found in the 46 kDa FAD-specific styrene epoxidase (SMOA) protein, comprises a part of the styrene monooxygenase (SMO) two-component flavoprotein monooxygenase enzyme. Structural analysis indicates that SMOA monomer comprises two globular domains spanned by a long alpha-helix. This domain contains a putative substrate binding site [1].

1: Structure and ligand binding properties of the epoxidase component of styrene monooxygenase . Ukaegbu UE, Kantz A, Beaton M, Gassner GT, Rosenzweig AC; Biochemistry. 2010;49:1678-1688. PMID:20055497