NMR study of the secondary structure of s‐RNA

The melting characteristics of unfractionated yeast s‐RNA in neutral aqueous solution have been examined by high‐resolution proton magnetic resonance spectroscopy. These studies indicate that the bases of s‐RNA become rotationally activated at lower temperatures than their associated ribose units. These observations, as well as the recently determined base sequence of an alanine‐specific s‐RNA, suggest that base complementarity may not be the primary determinant in the stabilization of the secondary structure of s‐RNA. In addition, evidence for exchange of C8‐protons of purine bases of s‐RNA with D2O was obtained at temperatures above 70°C.