Prolinyl Nucleotides Drive Enzyme-Free Genetic Copying of RNA

Area of Science:

• Biochemistry
• Origin of Life Studies
• RNA World Hypothesis

Background:

• Proline is a key proteinogenic amino acid with catalytic and structural roles.
• The origin of life likely involved interactions between amino acids and nucleic acids.
• Understanding primitive replication mechanisms is crucial for abiogenesis research.

Purpose of the Study:

• To investigate the potential of prolinyl nucleotides as building blocks for RNA replication.
• To explore enzyme- and ribozyme-free RNA copying mechanisms.
• To elucidate the role of organocatalysts in prebiotic chemistry.

Main Methods:

• Synthesis of prolinyl nucleotides with phosphoramidate linkages.
• Enzyme- and ribozyme-free RNA copying assays using template-directed incorporation.
• Utilizing monosubstituted imidazoles as organocatalysts in aqueous buffer.

Main Results:

• Prolinyl nucleotides (mono- and dinucleotides) were successfully incorporated into RNA primers.
• RNA copying occurred in up to eight consecutive extension steps, guided by a template sequence.
• Condensation products of amino acids and ribonucleotides mimicked nucleoside triphosphates in catalytic reactions.

Conclusions:

• Amino acid-ribonucleotide conjugates can function as activated building blocks in prebiotic RNA synthesis.
• Organocatalysis by imidazoles facilitates enzyme-free RNA extension.
• These findings support the hypothesis that combined amino acid and nucleic acid systems were selected during early molecular evolution.