Fig. 2: Bond length dependency on the separation distance of the G–C dimer.
From: Proton transfer during DNA strand separation as a source of mutagenic guanine-cytosine tautomers
Here, the separation distance is defined as the distance between the non-hydrogen bonded atoms participating in the hydrogen bonds) calculated by DFT. a The stretching of the canonical form of G–C from their unconstrained equilibrium lengths. The equilibrium lengths for the canonical base are 2.89 Å, 2.96 Å, 2.89 Å for B1, B2, and B3, respectively. b The stretching of the bonds of the tautomeric form of G–C, where two hydrogens have transferred. The equilibrium lengths are 2.61 Å, 2.89 Å, 3.01 Å for the tautomeric base. Whereas c and d show the structural changes of the G–C base’s canonical and tautomeric forms, respectively. During separation, the bond lengths and angle significantly change.
