Fig. 6: Structural basis for altered catalytic activity due to conformational changes.
a Structural alignment of active sites among GbCYP90J6 wild-type, high-activity mutant GbCYP90J6L382F, and low-activity mutant GbCYP90J6L382N. Regions targeted in alanine scanning were shown as cartoon representations, with L382, L382F, and L382N displayed as sticks. Critical distances were indicated in the lower left corner of each structure panel: d1 (distance between Fe = O and 4’-OH of 5D), d2 (distance between Fe = O and 7”-OH of 5U), and d3 (distance between C3’of 5D and C8” of 5U). These results demonstrated how single-point variations in the active site significantly altered both protein pocket and substrate conformations. b Structural comparison of active sites between functional amentoflavone synthases (GbCYP90J6 and ChCYP90J7) and inactive TcCYP90J7. Regions corresponding to the alanine scanning area in GbCYP90J6 were shown as cartoon representations. The three critical distances (d1, d2, and d3) were displayed in the lower left corner of each structural panel, highlighting conformational differences between active and inactive enzymes. c Binding free energies (kcal/mol) of ligand 1 (5D) and ligand 2 (5U) in GbCYP90J6, GbCYP90J6L382F, GbCYP90J6L382N, TcCYP90J7, and ChCYP90J7 as determined by gmx_MMPBSA analysis.
