Triplet Nucleotide–Amino-acid Pairing; a Stereo-chemical Basis for the Division between Protein and Non-protein Amino-acids

Abstract

Pelc and Welton have recently proposed¹ a stereo-chemical relationship between protein amino-acids and the codon triplet of nucleotides. I wish to propose a rather different possible relationship between nucleotide triplets and amino-acids which has emerged as a result of preliminary investigations aimed at understanding the usual exclusion and the occasional intrusion of the so-called non-protein amino-acids into protein.