How do the energetics of the stereoelectronic gauche and anomeric effects modulate the conformation of nucleos(t)ides?

The determination of the energetics of the temperature-dependent two-state N reversible arrow S pseudorotational equilibrium through (3)J(HH) analysis in 36 nucleos(t)ides and 3 abasic sugars has allowed us for the first time to quantify the strength of various nucleobase-dependent anomeric and gauche effects, and how their interplay finally steers the sugar conformation. The plots of the pD-dependent thermodynamics have given an independent method for the determination of pK(a)s of all naturally-occurring nucleobases showing that the energetics for the protonation reversible arrow deprotonation equilibrium is indeed transmitted through the anomeric effect to drive the two-state N reversible arrow S pseudorotational equilibrium (energy pump). This means that any change of the pK(a) of a specific nucleobase due to DNA/RNA folding, or H-bonding or any site-specific metal-ion complexation would promote specific local change of DNA/RNA conformation by transmission of the energetics of the altered aromatic character of the heterocyclic agycone to steer the sugar-phosphate backbone conformation through the tuning of the strength of anomeric effect.