[10] Conformation of tRNA and interaction with polynucleotide phosphorylase

Publisher Summary This chapter describes the degradation of tRNA by polynucleotide phosphorylase, and demonstrates the existence of two classes of conformational states of tRNA in solution defined by their sensitivity or resistance to the enzyme. The molecules resistant to polynucleotide phosphorylase attack are called R forms, and the molecules susceptible to enzyme degradation are called S forms; R and S, each represent a class of multiple conformational states. The elimination of the S forms at each temperature does not change the specific activity for the charging of the specific tRNA, suggesting that the configurations of tRNA in solution, discriminated by polynucleotide phosphorylase, are not distinguished by aminoacyl-tRNA-synthetases. The R and S forms have no apparent relation with the biological activity of tRNA, at least as tested in vitro .But, it is hoped that such a study has some interest insofar as the conceptual aspect of the problem of macromolecules interaction is concerned, and will contribute to insight of the properties of those molecules.