SPECIFICITY OF YEAST GLUTAMIC ACID TRANSFER RNA FOR CODON RECOGNITION

Two species of tRNA for glutamic acid (glutamic acid tRNA's I and III) were separated from yeast tRNA, and the stimulation of their binding to Escherichia coli ribosomes by the trinucleotides GpApA and GpApG, which are known to be codons for glutamic acid, was tested. The specificity of these two species of glutamic acid tRNA's for codon recognition was further studied by testing the transfer of glutamic acids to the specific amino acid position in rabbit hemoglobin by these tRNA species. The results of these studies showed that yeast glutamic acid tRNA's I and III specifically recognized the glutamic acid codons GpApG and GpApA, respectively. The codons for glutamic acid on the hemoglobin mRNA were tentatively assigned. It is the first clear demonstration that a codon containing adenosine residue in the third letter was specifically recognized by a tRNA. © 1969.