Figure 3
The CENP-A dimerization interface forms fewer and weaker contacts than the corresponding H3 interface.
(A) Contact map analysis illustrates the promiscuous interactions of His113/115 (circled) and contacts present in the dimerization interface of the H3 nucleosome but not in the corresponding interface of the CENP-A nucleosome (dotted lines). (B) Histograms demonstrate that the number of contacts formed at the CENP-A dimerization interface is fewer, on average, than at the corresponding H3 interface. (C) Crystal structure dimerization interfaces for the CENP-A (dark orange) and H3 (light orange) nucleosomes highlight that the four helices composing the CENP-A:CENP-A’ interface are less well-defined than the four helices composing H3:H3′. Residues Arg 116 and His’ 113 of H3:H3′, as well as Arg 118 and His’ 115 of CENP-A:CENP-A’, are shown as sticks. The dashed lines represent the pseudo-dyads. Structure figures rendered in Pymol.
