SAXS data for sites I, II, and III. (A) SAXS data for sites I, II, and III (SI, SII, and SIII, respectively). SAXS curves have been shifted on the y axis for clarity. (B) Rigid-body modeling results shown as a plot of the χ of the fit of each DNA structural model (DNAψ, see Materials and Methods) as a function of the kink angle ψ when fitted to the experimental datasets from sites I (down triangles), II (open squares), and III (open circles).