Interestingly, the analysis of the conformation of the adjacent residue within the activated dinucleotides demonstrates that the C3 ′ -endo is dominant (92.5 %) only for the parent GpAIpG system, which is consistent with the recent work of Mittal et al. . The population of the C3 ′ -endo conformation in the adjacent nucleotide is much lower for all remaining activated dinucleotides. Most of these dinucleotides are characterised by somewhat higher population of the C2 ′ -endo arrangement in the adjacent nucleotide. Only the ApAIpA dinucleotide interacting with the tUtU templates does not sample the C2 ′ -endo conformation for the adjacent nucleotide, with 31.5 % of the population reaching the C3 ′ -endo conformation and the remaining frames sampling values of the C1 ′ -C2 ′ -C3 ′ -C4 ′ dihedral angle, which are between the two ribose conformers.