Nuclear Overhauser effect study of yeast aspartate transfer ribonucleic acid

Abstract

Nuclear Overhauser effect (NOE) studies are described for yeast tRNAAsp in 0.1 M NaCl, pH 7.0. A primary aim is to develop a general method for attacking the problem of assignment in tRNA. Previously, the utility of the NOE between protons on adjacent base pairs [bp] combined with C8 deuterium substitution was demonstrated by assigning the imino protons of the dihydrouridine stem and the 2 reverse-Hoogsteen bp T54-A58 and U8-A14. Here, that approach is extended to other parts of the molecule. For the 1st time, a purine-15-pyrimidine-48 bp (in this case A15-U48) has been assigned. A total of 13 of 25 bp from all parts of the molecule and several noninternally bonded imino protons have now been assigned unambiguously. This is a general method for assigning resonances in tRNA and perhaps in all double-stranded nucleic acids. This, and the distance information inherent in NOE measurements, should make NMR more generally applicable to nucleic acids.