Prebiotic Assembly of Cloverleaf tRNA, Its Aminoacylation and the Origin of Coding, Inferred from Acceptor Stem...

Area of Science:

• Origin of Life
• Prebiotic Chemistry
• Molecular Evolution

Background:

• Transfer RNA (tRNA) is essential for protein synthesis, translating messenger RNA (mRNA) into amino acid sequences.
• The prebiotic origins of tRNA, including its formation, aminoacylation, and the coding triplets, remain largely unexplained.
• Understanding these early molecular events is crucial for deciphering the emergence of life.

Purpose of the Study:

• To investigate the prebiotic materialization of tRNA and the origin of its coding triplets.
• To propose a model for the emergence of a proto-tRNA capable of self-aminoacylation.
• To explore how these early molecules and processes could have arisen through natural means.

Main Methods:

• Analysis of conserved coding triplet patterns in the acceptor stems of modern bacterial tRNAs for five early-emerging amino acids.
• Modeling the self-assembly of short RNA oligonucleotides with related coding patterns.
• Evaluating the statistical feasibility of this self-assembly process for generating a proto-tRNA structure.

Main Results:

• A conserved pattern of coding triplets in tRNA acceptor stems suggests a specific prebiotic origin.
• Self-assembly of RNA oligonucleotides can statistically form a proto-tRNA model compatible with modern cloverleaf structures.
• These stem coding triplets may have enabled self-aminoacylation of proto-tRNAs before the evolution of synthetase enzymes.

Conclusions:

• The proposed proto-tRNA model offers a plausible pathway for the autonomous materialization and self-aminoacylation of early RNA molecules.
• This model provides key components for understanding the emergence of the genetic code and the origin of life.
• The findings support a naturalistic origin of life, driven by self-assembly and self-functionalization processes.