Specificity in the Structure of Transfer RNA

Abstract

This chapter discusses the recent work on the specificity embodied in the structure of transfer RNA (tRNA). The chapter also discusses the base composition of tRNA. The numerous analyses of the base composition of bulk tRNA preparations from different sources have been reviewed in this chapter. The various arrangements of nucleotides in tRNA are also discussed in this chapter. Counter-current distribution, column chromatography, and other separation techniques have been used in the fractionation of tRNA's. Some of them are highly specific for one particular amino acid. The base composition of these fractionated tRNA's is characteristic. The arrangement of nucleotides in tRNA, such as (a) nucleotide distribution, (b) anticodon sequence, and (c) terminal nucleotide sequences, are discussed in this chapter. Although a definite tertiary structure of tRNA has not yet been defined, each specific tRNA, which has a specific base composition, may have a specific tertiary configuration, because the melting profiles of a few specific tRNA's differ from each other. The chapter also describes various three-dimensional structure of tRNA. The chapter concludes with the modification of nucleic acid bases, without scission of the polynucleotide chain, and the resulting change in the biological activities of nucleic acids from viruses or bacteria. In order to elucidate the functional sites of tRNA, it seems logical to examine the change in the activity of such modified tRNA.