On the Origin of Protein Synthesis: A Speculative Model Based on Hairpin RNA Structures

A speculative model for the origin of protein synthesis based on aminoacylated hairpin RNAs is presented. The model shows how dimerization of these hairpin structures might have triggered the initial synthesis of oligopeptides. The evolution of these dimers seems to lead naturally both to the origin of the tRNA molecule and to the origin of protein synthesis. This co-evolution seems to be confirmed in the determinants of the tRNA identity that might represent the vestiges of the hypothesized model. Finally, the model lends itself to direct experimentation.