Fig. 4: Competitive potential of transcription factor binding to RCD1.
Different amounts of residual α-helix structure in the unbound state of transcription factors of the RCD1-interactome result in different affinities and amounts of induced structure upon binding. Here illustrated for both the natural occurring helicity within DREB2 transcription factors and the designed DREB2A variants used in this study. The higher the α-helix amount in the unbound state (color gradient), the higher the affinity, manifested in a smaller koff and hence slower off-rates (illustrated by the size of the equilibrium arrows). Higher α-helix amount in the unbound state, is further correlated with a more stabilized C-terminal part of the induced helix. This suggests a core unit and a regulatory region in the bound α-helix. Together, this translates into different competitive potentials of transcription factors binding RCD1.
