Role of Nucleic Acid and Enzymes in Peptide Chain Synthesis

Abstract

RECENTLY, there has been much discussion of possible mechanisms whereby the order of the nucleotide sequence in a polynucleotide chain might determine the order of the amino-acid sequence in a peptide chain. The polynucleotide molecule is assumed to be the template or pattern for the peptide chain. In a mechanism proposed by one of us¹, enzymes were assumed to play an important part in attaching the amino-acids to the polynucleotide chain; as many enzymes would be required for this purpose as there are nucleotide combinations corresponding to amino-acids. In a system where a nucleotide triad is assumed to correspond to a given amino-acid, there must be as many enzymes as there are triads, and it can be shown that more than one triad would have to correspond to a given amino-acid in order to permit the occurrence of a reasonably large number of possible neighbours on either side of a given amino-acid in a peptide chain (unless it is postulated that there is to be no overlapping of the triads).