Fig. 1: The separation scheme used to investigate how the canonical and tautomeric G–C base-pairs separate.
From: Proton transfer during DNA strand separation as a source of mutagenic guanine-cytosine tautomers
Four G–C base pairs of the 14 base-pair DNA duplex used in the molecular dynamics simulations are shown, with a separating force (red arrow) applied to the first base pair’s (G0–C0) backbone. DFT calculations were performed only on base-pair G1–C1, where atoms marked with the lock icon were fixed. We define the three hydrogen bonds; Bond 1 (B1) as the distance measured from DG:O6-DC:N4, Bond 2 (B2) from DG:N1-DC:N1, and Bond 3 (B3) DG:N2-DC:O2. The opening angle θ measures the asymmetry with which the hydrogen bonds stretch.
