As a result of damage (usually deamination), DNA will sometimes contain uracil and inosine bases. I am trying to determine which unnatural base pairing combo would be more stable: uracil paired with guanine or inosine paired with cytosine. See the images below.
One can discuss the strength of H-bonds, but that would be half of the picture. It is more important how well (or poorly) this pair fits in the whole helical structure. Stacking interactions (arene-arene interactions) are playing important role in stabilization of DNA. If the pair disturbs backbone shape the binding will be poor. Google scholar search for relevant papers might be the most productive way to go.
