Fig. 4.

Comparison of models to raw images of folded chromatin. (A) Electron cryo-microscopy images of a folded chromatin array containing 22 nucleosomes with a repeat length of 177 bp. The particles are visualized unperturbed in the frozen hydrated state and oriented randomly in ice containing 1.0 mM Mg²⁺. The particles in each row represent similar views. (Scale bar: 100 nm.) (B) Views of the interdigitated one-start helix model (Fig. 3A) that closely match the EM images from the corresponding row in A. (C) Views of the adapted two-start crossed-linker model (Fig. 3B) that are equivalent to those of the interdigitated model from the corresponding row in B. The varying orientation of the coordinate axes describes the three-dimensional orientation of the models in the corresponding rows.