Fig. 8. Helical exchange dynamics of MITF in the absence of ligands.

a Model of MITF(206-296) bound to the M-box DNA sequence and scheme indicating the helices’ exchange. One helix is displayed as a dashed red line, and the other as a solid blue line. Both experience the kinked and straight conformation. b The ¹H,¹³C-HMQC NMR spectrum of MITF(217–296) in the absence of ligands and DNA shows a single set of peaks, indicating rapid conformational exchange of straight and bent helices. Selected resonance assignments are indicated. c MD simulations of apo MITF in the presence of M-box DNA, indicating rapid helical exchange. The distance between the Cα of S250 and L282 for each helix (a) is plotted in blue and red for the two helices.