(A) Location of the IE1-CTD binding site on the acidic patch of the nucleosomal surface. The histone octamer is shown as a surface representation colored according to electrostatic potential distribution (positive, blue; neutral, white; negative, red). DNA is shown as a cartoon colored white, and IE1-CTD is shown as a stick model. (B) A detailed view of the interaction between IE1-CTD and NCP. Histones H2A and H2B are shown in a ribbon representation superimposed with selected residues (in sticks) involved in interaction with IE1-CTD. Dashed lines indicate hydrogen bonds. An enlarged view of the region surrounding His481 of IE1-CTD is shown in an inset at the bottom of the figure. (C) Superposition of IE1-CTD and LANA. Both peptides are shown as a ribbon representation superimposed with sidechains (IE1-CTD, green; LANA, blue). (D) Structure-based alignment of IE1-CTD and LANA sequences. Residues colored in red are involved in similar interactions with the histones, and the two residues colored in magenta are engaged in IE1-CTD-specific interactions with histone H2A.