Changing the Identity of a tRNA by Introducing a G-U Wobble Pair Near the 3′ Acceptor End

Abstract
Although the genetic code for protein was established in the 1960's, the basis for amino acid identity of transfer RNA (tRNA) has remained unknown. To investigate the identity of a tRNA, the nucleotides at three computer-identified positions in tRNA Phe (phenylalanine tRNA) were replaced with the corresponding nucleotides from tRNA Ala (alanine tRNA). The identity of the resulting tRNA, when examined as an amber suppressor in Escherichia coli , was that of tRNA Ala .