Simple peptides derived from the ribosomal core potentiate RNA polymerase ribozyme function.

Area of Science:

• Origin of Life Studies
• Biochemistry
• Molecular Biology

Background:

• Functional interactions between nucleic acids and polypeptides are central to biology.
• The role of simple, non-coded peptides in early RNA function is not well understood.

Purpose of the Study:

• To investigate how simple peptides influenced early RNA function and the emergence of protocells.
• To determine if ancient peptide segments and specific amino acids enhance RNA polymerase ribozyme (RPR) activity.

Main Methods:

• Tested putative ancient peptide segments and homopolymeric peptides (lysine, ornithine, diaminobutyric acid) for their effect on RPR function.
• Assessed peptide impact on holoenzyme assembly, primer-template docking, RPR evolution, and RNA synthesis efficiency.
• Evaluated RPR activity under varying magnesium (Mg2+) concentrations.

Main Results:

• Ancient peptide segments and lysine, ornithine, and diaminobutyric acid peptides significantly enhanced RPR function.
• Lysine decapeptides promoted holoenzyme assembly via primer-template docking and accelerated RPR evolution.
• Peptides enabled RPR-catalyzed RNA synthesis at physiological Mg2+ concentrations (≥1 mM), facilitating templated synthesis within protocells.

Conclusions:

• Compositionally simple, mixed-chirality peptides likely augmented early RNA functional potential.
• These peptides played a crucial role in the emergence and function of the first protocells.
• The findings provide insight into the transition from non-coded peptides and RNA to early biological systems.