The driving force for molecular evolution of translation

Area of Science:

• Origin of Life
• Biochemistry
• Molecular Evolution

Background:

• The prevailing hypothesis suggests protein synthesis evolved from an RNA world, where RNAs performed functions now handled by proteins.
• A key evolutionary question is the selective advantage for developing primitive translation, as early polypeptides likely offered limited biological utility.

Purpose of the Study:

• To propose a novel hypothesis for the evolution of translation.
• To suggest that early peptides expanded the structural and functional repertoire of the RNA world, rather than aiming to create a protein-dominated system.

Main Methods:

• Theoretical modeling of RNA structure space.
• Analysis of existing literature on RNA-peptide interactions.
• Review of experimental evidence for peptide-induced RNA structural changes.

Main Results:

• The study posits that even simple peptides could significantly increase the structural diversity accessible to RNA.
• This expansion of RNA structure, facilitated by peptides, would have enhanced its functional capabilities.
• Observed instances of peptides inducing significant structural rearrangements in RNA support this hypothesis.

Conclusions:

• Translation may have initially evolved as a mechanism to augment the RNA world's capabilities.
• The primary driver for early translation was likely the extension of RNA's structural and functional potential.
• This perspective reframes the evolutionary trajectory from an RNA world to a protein world.