Figure 4
From: Cryo-EM of nucleosome core particle interactions in trans
H4 tail makes weak interactions with H2A/H2B or DNA. (A) A slice through the NCP pairs of classes A1-A5 showing weaker interactions at the histone octamer interface. These contacts are presumably formed by the histone H4 tail of one NCP and the H2A/H2B acidic patch or the DNA of the second NCP. The cryo-EM density for both NCPs is shown in transparent blue. The molecular model for NCP 1 is shown in blue and for NCP 2 in red. (B) The cryo-EM map of the combined reconstruction of the classes A1–A3. On the histone octamer side without the adjacent NCP 2, the strong density where the N-terminus of H4 interacts with DNA at superhelix SHL 2 is visible. On the opposite side, with the adjacent NCP 2, the density for the H4 tail is not visible. This indicates that the H4 tail dissociates from the DNA of the NCP 1 and engages in intra-nucleosomal interactions.
