Amino acid-directed nucleic acid synthesis. A possible mechanism in the origin of life.

The fact that proteins contain only alpha-amino acids and that protein structure is determined by 3' leads to 5' linked ribonucleotides is postulated to be the result of the copolymerization of these molecules in the prebiotic environment. Ribonucleotides therefore represent partial degradation products and proteins represent a side reaction developing from copolymerization. The basic structural unit of copolymerization is a nucleotide substituted with an amino acid at the 2' postion. Characteristics of modern amino and ribonucleic acid structure are all consistent with and necessary for this hypothesis. The characteristics and individual base assignemnts of the code also provide strong support for origin from the postulated copolymers. All characteristics of the code can be accounted for by this single hypothesis.