Figure 4.

Influence of non-zero Slide and Roll at sequential dimer steps on overall DNA helical conformation. Images generated with 3DNA building upon the principles of Calladine and Drew (42). The radii of the (dashed) circles in the upper row of images, defined by the loci of points from the helical axes (filled circles) to the base pair origin (open circles), correspond to the x-displacement. The values of dimeric Twist are adjusted, following equation 4, to keep the helical twist angle at 36°. The A-like model is highlighted in quotes to emphasize that the structure contains 10 rather than 11 residues per turn.