Fig. 2. Schematic representation of the parameters used to define the flap-structure motion: d1 the distance between the flap tip and flexible region hinge residue, the dihedral angle Φ and the TriCα angles, θ1 and θ2. Asp1, Asp2, the flap tip and flexible region of PMIX are presented in gold with the respective regions of PMX represented in red.
