ON THE ROLE OF SOLUBLE RIBONUCLEIC ACID IN CODING FOR AMINO ACIDS

Abstract

In protein synthesis, each amino acid is first joined specifically with a corresponding sRNA through the mediation of an activating enzyme. These aminoacyl-sRNA's, by reaction with a ribosomal preparation, form proteins with specific amino acid sequences. According to the "'adaptor" hypothesis of Crick and Hoagland, the position of a particular amino acid would be determined not by the amino acid itself, but by hydrogen bonding between the RNA template and a complementary nucleotide sequence in the sRNA carrying the amino acid. The experiment described in this paper was designed as a direct test of the adaptor hypothesis, by attaching an amino acid to its normal sRNA and then, without breaking the bond, converting the amino acid to another one of the natural amino acids. It is then possible to determine whether the coding properties of this hybrid are determined by the sRNA or the amino acid. We have made use of the fact that cysteine can be altered by reductive desulfhydration with Raney Nickel to alanine.