Methyl-1 guanosine (m 1 G) mutations reveal two states dominating the conformational ensemble. To validate the orientations of the internal loop residues predicted by T-REMD calculations (Figure ), we performed NMR studies on a number of singly and doubly modified RNA samples. We selected m 1 G modifications, which inhibit hydrogen bond donation from modified nucleotides (Figure ). Using this modification in the context of the 2×2 GG/GG internal loop, we anticipated that m 1 G-modified nucleotides will adopt the syn conformation,