Rapid Identification of Noncanonical RNA Structure Elements by Direct Detection of OH⋅⋅⋅OP, NH⋅⋅⋅OP, and NH2⋅⋅⋅OP Hydrogen Bonds in Solution NMR Spectroscopy

Hydrogen bonds involving phosphate groups as acceptors only occur in noncanonical structure elements of RNAs and are important for their stable folding. These hydrogen bonds can be directly assigned by H,P correlation experiments in solution NMR spectroscopy owing to the presence of sizeable 2hJHP scalar couplings across the hydrogen bond. These experiments will provide valuable information to speed up the determination of complex RNA structures.