Effects of Aminoacylation and Solution Conditions on the Structure of tRNA

Abstract

The bulk of the work performed to date on the solution structure of tRNA has quite naturally been directed toward the elucidation of the tertiary structure and the identification of functionally important structural features. With the recent elucidation of the crystal structure of tRNA (Quigley et al. 1975; Ladner et al. 1975) and the recognition that that structure is also obtained in solution (Chen et al. 1975; Robillard et al. 1976; and see results from less direct experiments reviewed by Rich and RajBhandary 1976), it is now possible to approach many other outstanding questions of tRNA structure in ways previously not possible. Of special and long-standing interest are questions related to (1) the effects of solution conditions on tertiary structure, (2) the tertiary structures of aminoacyl- and peptidyl-tRNAs and precursor tRNA, and (3) the molecular nature of the protein-nucleic acid interactions in which tRNA participates in the course of being synthesized, utilized, and degraded. Because at least some, and perhaps all, of these phenomena are likely to involve dynamic changes in tertiary structure, it will be important to study these questions with biophysical and chemical techniques that are sensitive to different features of the solution structure and that allow analyses to be conducted under physiological solution conditions.

Here we review results from our investigations into the effects of aminoacylation and solution conditions on tRNA structure, utilizing the relatively new technique of laser light scattering. This technique is especially well suited for the assessment of structural transitions of biomolecules in solution.