The nucleosome core particle (NCP) structure was obtained from PDB file 1AOI, and was solvated in a periodic orthorhombic box containing approximately 76500 water molecules (157 Å × 167 Å × 113 Å). The DNA fragment was composed of 146 base pairs. The total charge was neutralized using Na + ions, while additional Na + and Cl -ions corresponding to a biologically relevant concentration of 150 mM 72 were also added. The simulated systems consisted of approximately 252'465 atoms in total. A visualization of the entire periodically repeated box is shown in Figure . To assess the effect of specific NCP locations on the change of the DNA redox properties, two different guanine-rich regions were considered. These two regions were the only areas in the 1AOI.pdb with three adjacent guanine bases. They respectively comprise residues 58-60/233-235 (5'-GGC-3'/5'-GCC-3') and 87-89/204-206 (5'-GCC-3'/5'-GGC-3'). In the rest of the manuscript, these two regions will be respectively referred to as region 1 and region 2, (and they are shown in red and orange color in Figure ). Both regions were selected within DNA helices firmly wrapped around the histone proteins, and not near the more flexible tails. However, the regions differ in their number of interactions with the histone proteins (see Tables 3-4 in the SI). Region 1 is found to have more interactions with nearby histone proteins and therefore could be consider less solvent accessible than region 2. Furthermore, the three base pairs of region 2 have a greater number of average hydrogen-bonding interactions with solvent molecules than the three base pairs of region 1 additionally indicating that region 2 is more solvent exposed than region 1 (see Table in the SI). In the respective defect systems, the central G of each region (G59 in region 1 and G205 in region 2) was replaced by an 8oxoG defect (shown in a representative manner for region 2 in Figure ).