FIGURE 1.

Schematic representation of filtering strategy. Beginning with a high-resolution structure of the nucleosome (top left) the DNA helical parameters (Shift, Slide, Rise, Tilt, Roll, Twist) are extracted using 3DNA (27) (bottom left). The helical parameters are subjected to Fourier filtering (33) (bottom right) and used to recreate an atomic model of the DNA superhelix, 3DNA⁻¹ (top right). The RMSD between the reconstructed superhelix and the input structure is calculated (34) and utilized to assess the effect of the filter. The filtering has two stages: the first creates knock-outs and the second creates knock-ins, as described in Methods.