Recognition of tRNAPhe by phenylalanyl-tRNA synthetase of Thermus thermophilus

Abstract

The tRNA(Phe) nucleotides required for recognition by phenylalanyl-tRNA synthetase of Thermus thermophilus have been determined using Escherichia coli tRNA(Phe) transcripts with various mutations. The anticodon nucleotides are shown to be the most important recognition elements. The discriminator nucleotide, A73, involved in the recognition set of yeast, E. coli and human phenylalanyl-tRNA synthetases contributes only slightly to tRNA(Phe) recognition by Th. thermophilus phenylalanyl-tRNA synthetase. Nucleotide 20 and some tertiary nucleotides, including the conserved G19.C56 base pair, are proposed to participate in stabilization of the precise tRNA conformation required for efficient aminoacylation. The role of the 3'-CCA terminus, common to all tRNAs, in the specific interaction of tRNA with phenylalanyl-tRNA synthetase is discussed.