Figure 3.

Dinucleotide conformations in the crystal structure of the histone-core particle 1KX5 (89). Dinucleotides are classified into four conformational families and labeled as follows: BI–1, BII–2, BI conformers with a α + 1/γ + 1 switch (Clusters 113–117) – 3, unclassifiable conformers – 4. One DNA chain, labeled I in the PDB file and drawn in blue and marked in the left y axis in the Figure, is traced from the 5′-end to the 3′-end. The other chain, labeled J in the PDB file and drawn in red in the right y axis, is traced from the 3′-end to the 5′-end. Base paired nucleotides from chains I and J have therefore the same x coordinate.