Adx and substrate exert a coordinated effect on CYP24A1 structure. (A) EDC reactivity of CYP24A1 was compared with and without substrate (left), where no difference was observed, and with or without substrate but in the presence of Adx (right), where four peptides (B) were differentially affected. Mapping of the peptides across the A, C-D, F, and G helices are shown in (C) and as a surface representation in (D).