A hypothesis: reciprocal information transfer between oligoribonucleotides and oligopeptides in prebiotic molecular evolution.

We wish to propose a mechanism for reciprocal information transfer in prebiotic molecular evolution, based on heterologous pairing complex formation between oligoribonucleotides and oligopeptides. In this proposed pairing complex, the bases of the oligoribonucleotide and the side chains of the oligopeptide may form three types of complementary Watson-Crick-type hydrogen bonds. The structural basis for the pairing is the close correspondence of the distances between the side chains in the two molecules. Both the inter-nucleotide spacing of the RNA and the inter-side-chain spacing of the peptide are approximately 3.4 A. The proposed pairing mode would allow both specific and nonspecific interactions required for reciprocal information transfer. Thus, it represents a simple and versatile coding system that could have had significant implications in prebiotic molecular selection and evolution. In addition, we propose several testable experimental approaches based on the pairing mode of oligoribonucleotides and oligopeptides to verify our hypothesis.