Figure 4.

Crystal structure of AncFMO1 and its active site.A, dimeric AncFMO1 with its partially mapped C-terminal helices pointing downward toward the membrane. B, the active site of AncFMO1 in the presence of oxidized coenzyme, NADP⁺, and two glycerol molecules (green) is depicted, with the key residues labeled. C, extensive hydrogen bond interactions between E281, N61, V59, FAD, NADP⁺, and a glycerol molecule are shown to illustrate key intermolecular interactions and potential substrate binding modes, represented by dashed yellow lines. FAD, NADP⁺, and DDM molecules are colored in yellow, cornflower blue, and white, respectively. AncFMO, ancestral flavin-containing monooxygenase; DDM, dodecyl-β-D-maltoside; FAD, flavin adenine dinucleotide.