On some predictions of the poly-tRNA model for the origin and evolution of genetic coding

TL;DR

This paper discusses the poly-tRNA model for the origin and evolution of genetic coding, highlighting its implications for early life, RNA world interactions, and the emergence of functional peptides that drove the development of protein synthesis.

Contribution

It extends the poly-tRNA model to explain early life development, RNA-protein interactions, and the origin of functional peptides in the evolution of genetic coding.

Findings

Protein synthesis likely started in a rich RNA world.

Early peptides had unique properties linking RNA and membranes.

The model suggests peptides influenced Darwinian selection of synthesis machinery.

Abstract

The poly-tRNA model was recently presented for the origin and evolution of genetic coding. This model has led to a rather precise description of what might have occurred at the beginning of protein synthesis in the first life form. Here, we further discuss some interesting implications of this model. First, the system of encoded peptide/protein synthesis appears to have started and developed on the breeding ground of a rich RNA world, responsible for the infancy of life existence and complexity. Furthermore, once protein synthesis was fully established and apparently superseding the RNA world, and at a very early stage of life beginnings, we already see what has been a recurrent theme in the likely interpretation of modern comparative molecular studies on species: the full ability of this nascent life entity to develop itself by tinkering, using all kinds of available pieces to improve itself. Lastly, and very instructively, it is deduced from this model that the first peptides to be produced probably had unique properties, not shared by the arsenal of molecules present hitherto, which allowed a functional connection between the then omnipotent RNA world and the lipid membrane vesicles containing it. These specific functions might have initially been at the origin of the Darwinian selection of the full-blown protein-synthesis machinery.