Fig 1: HMCES-DPC at ssDNA gaps reduces nucleosome density in fork reversal-deficient cellsA) APOBEC3B and HMCES levels on nascent DNA measured by iPOND-SILAC-MS. N = 4.B) RADAR assay detecting HMCES-DPC in WT and FRKO cells. N = 3.C–E) PLA for EdU and H3 in indicated conditions (as in Figure 1B). N ⩾ 7. p-values from Kruskal–Wallis test.F–G) Nucleosome reconstitution assays showing nucleosomes fail to form on dyad ssDNA gaps but can form at side gaps. Gels show NCP bands. AP-DNA represents abasic-site DNA; AP-NCP represents nucleosomes assembled on abasic DNA. L represents ladder, D is DNA, N is nucleosome.H) Model schematic of how ssDNA adducts interfere with nucleosome formation at gaps.