Two-dimensional NMR for three-dimensional structure of nucleic acids: new techniques and novel results

Abstract

The principles and the variety of two-dimensional (2D) NMR techniques useful for structure determination of nucleic acids have been described. Three new techniques namely, SUPERCOSY, J-scaled COSY and COSS which have been recently developed to overcome the problems of sensitivity and resolution have been described in greater detail. The strategies of resonance assignments and structure determination of nucleic acids have been discussed and the experimental results on four oligonucleotides longer than a complete turn of nucleic acid helix have been presented. The data indicate O I' -endo sugar geometry in a majority of the nucleotide units in two oligonucleotides namely, d-GAATTCGAATTC and d-GAA TTCCCGAATTC.