FIGURE 5.
DNA-PK P-H2A.X nucleosome (nuc.) core particles are less stable compared with the H2A.X or H2A nucleosome core particles. A, shown is native 4% PAGE analysis of NCPs, in comparison to NCPs, reconstituted with H2A.X or with γ-H2A.X and a 146-bp random sequence DNA. CFO is a CfoI-digested pBR322 plasmid DNA used as a marker. B, NaCl dependence of the sedimentation coefficient (s20,w) of native NCPs and NCPs reconstituted with H2A.X or with P-H2A.X is shown. Sedimentation velocity experiments were carried out at 40,000 rpm at 20 °C in different NaCl concentrations in 10 mm Tris-HCl and 0.1 mm EDTA (pH 7.5) buffer. D, area of the scan corresponding to material sedimenting as free DNA; N, peak in the scan corresponding to NCPs. C, shown is the percentage of non-dissociating H2A.X/P-H2A.X-containing nucleosomes at different NaCl concentrations calculated from the relative area under peak N of the sedimentation velocity profile shown in B.