1.14.13.29 FAD - 1.14.13.29 FAD flavoprotein, FMN cannot replace FAD 1.14.13.29 FAD FAD binding site structure of PnpA1, molecular docking of FAD, overview 1.14.13.29 FAD the si-side of FAD is exposed to solvent, and the re-side faces the substrate-binding site. The loop from positions 449 to 454, loop 187-201, helices alpha13, alpha14, and loop 154-175 are responsible for coordinating FAD. The former three interact with the isoalloxazine ring of FAD, while the latter two interact with the AMP group 1.14.13.29 NAD(P)H - 1.14.13.29 NADH - 1.14.13.29 NADPH - 1.14.13.29 NADPH 50% of the activity with NADH