Computational study of hydrogen-bonded complexes between the most stable tautomers of L-leucine and bases of RNA

A total of 16 hydrogen-bonded complexes between the lowest energy tautomers of L-leucine and each base of RNA have been characterized at the DFT level of theory. The most stable complexes are formed by L-leucine and guanine. Considering backbone of RNA, the affinity order between the L-leucine and bases is guanine> cytosine> adenine≈uracil in perfect accordance with the experimentation. The interplay between the transformed H–X bonds’ structural parameters from two monomers to the dimer accompanying with the shifts of the frequency for the H–X stretching mode and interaction energies has been discussed.