High-resolution phosphorus nuclear magnetic resonance spectra of yeast phenylalanine transfer ribonucleic acid. Metal ion effects and tentative partial assignment of signals

Abstract

The temperature and metal ion dependence of the 31P NMR spectra of yeast phenylalanine tRNA is presented, and a tentative assignment of some of the individual phosphate signals is offered. Signals A, C, F, P and T were assigned to the Mg binding site phosphates by monitoring the Mg2+ dependence in the 31P NMR spectra. In the presence of 10 mM Mg2+, specific paramagnetic line broadening effects are observed for signals A, D, E and U upon addition of 0.001-0.1 Mn2+/tRNA molecule. Through the combination of the above metal ion experiments, X-ray studies, and earlier 1H and 31P NMR studies [particularly the tRNA modification 31P NMR experiments of Salemink, et al. [Salemink, Swarthof and Hilbers (1979)]], an initial assignment of some of these signals is attempted.