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Figure 4
(A) P(r) derived for atoms only on the backbone (backbone–backbone pairs) for AT DNA with selected peaks highlighted (10–11, 19–20, 24–25 and 28–29 Å). Representative distances are visualized in atomic models using ChimeraX, illustrating separations spanning the minor groove, the cross-duplex helical radius, the major groove and the same-strand helical radius, respectively. (B) P(r) derived for atoms only associated with the base (base–base pairs) for AT DNA, highlighting peaks at 7–8, 17–18, 27–28 and 37–38 Å, corresponding to bases separated by 2, 5, 8 and 11 nucleotide steps along the duplex, respectively. (C), (D) Residue-index correlation maps for AT DNA and Mix DNA at 18–20 Å, showing highly regular ladders of backbone–backbone pairs in AT DNA and distorted irregular patterns in Mix DNA indicative of increased backbone heterogeneity. (E), (F) Residue-index correlation maps for AT DNA and Mix DNA at 52–54 Å, revealing long-range base-stacking correlations in AT DNA that are broadened and disrupted in Mix DNA.

IUCrJ
Volume 13| Part 5| September 2026| Pages 650-658
ISSN: 2052-2525
https://doi.org/10.1107/S2052252526007700