Nucleotide conformations in codon-anticodon interactions

Abstract

The amount of distortion required of the sugar-phosphate backbone in RNA double-helices to accommodate various non-standard base pairs was examined by means of a linked-atom least-squares computer program. Compressive pyrimidine-pyrimidine pairs were found to entail more strain than the extensive adenine-hypoxanthine pair, as predicted by the wobble hypothesis. Purine-pyrimidine pairs involving guanine and uracil also require little torsional strain, indicating the acceptability of such pairings in hairpin stems as well as in codon-anticodon bindings.