Ribonucleic acids may be catalysts for the preferential synthesis of L-amino acid peptides: a minireview

Abstract

This minireview is a summary of the basic concepts and pieces of experimental evidence supporting a hypothesis that suggests a mechanism whereby purine monoribonucleotides having D-ribose may be able to preferentially catalyze the synthesis of L-amino acid peptides. The proposed mechanism involves a 2'-3' diaminoacyl intermediate and the preference accrues from several factors that favor the L-isomer, principally for hydrophobic amino acids. Although the hypothesis has not been fully tested, some crucial evidence has been published. Other pieces of evidence are now being submitted or are in press for publication and still other experiments, principally on the step of peptide bond formation, are in the process of being carried out. The purpose of a review at this point is to present the hypothesis to the scientific community in hopes of generating discussion, suggestions, and evaluation by other workers. Should the hypothesis prove correct, it may represent the most primitive and fundamental relationship between the nucleic acid and protein systems. In addition, it would represent another important example of the catalytic ability of RNA.