Evolution of the genetic code. From the CG- to the CGUA-alphabet, from RNA double helix to DNA

TL;DR

This paper proposes a comprehensive hypothesis on the evolution of the genetic code, explaining its stability, structural features, and the transition from RNA to DNA, based on nucleotide damage and mutation processes.

Contribution

It introduces a novel evolutionary model linking nucleotide damage to genetic code development, including the origin of DNA, stop codons, and code dialects.

Findings

Genetic code stability explained by mutation mechanisms

Emergence of stop codons and DNA double helix modeled

Primary structure of first gene and protein hypothesized

Abstract

A hypothesis of the evolution of the genetic code is proposed, the leading mechanism of which is the nucleotide spontaneous damage leading to AT-enrichment of the genome. The hypothesis accounts for stability of the genetic code towards point mutations, the presence of code dialects, emergence of stop codons, emergence of the DNA double helix and the symmetry of the genetic code table. The assumption of the originally triplet structure of the genetic code has been substantiated. A hypothesis concerning the primary structure of the first gene and the first protein has been proposed.