FIGURE 4.

Binding of NADP⁺ analogues to mFMO. A, chemical formulas of the two compounds using for this study (APADP⁺ on the left and thioNADP⁺ on the right). B, structure of the complex with APADP⁺ in approximately the same orientation and coloring scheme as in Fig. 1B. The carbons of APADP⁺ are in green. H-bonds are shown as dashed lines. C, comparison between the binding of NADP⁺ and APADP⁺ using a composite picture that shows the protein surface of the wild-type protein bound to NADP⁺ (carbons in cyan) and FAD (carbons in yellow). The pyridine ring of APADP⁺ is superimposed to highlight its different position at the rim of the active-site cleft surface. The NADP⁺ and APADP⁺ complexes are very similar (root-mean-square deviation of 0.21 Å for the Cα atoms).