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Codon assignment evolvability in theoretical minimal RNA rings.
Jacques Demongeot1, Hervé Seligmann2
1Université Grenoble Alpes, Faculty of Medicine, Laboratory AGEIS EA 7407, Team Tools for e-Gnosis Medical, F-38700 La Tronche, France.
Gene
|October 8, 2020
Summary
Genetic code evolution favors specific codons, particularly those rich in cytosine, influencing RNA ring structures and their amino acid assignments. These findings reveal insights into the standard genetic code and RNA evolution.
Area of Science:
- Genetics
- Molecular Biology
- Bioinformatics
Background:
- The genetic code, which translates nucleotide sequences into amino acid sequences, has evolved over time.
- Understanding the evolution of codon assignments is crucial for deciphering molecular mechanisms and origins of life.
- Existing research has cataloged various genetic codes, but their evolutionary drivers and structural implications remain areas of active investigation.
Purpose of the Study:
- To investigate the evolutionary patterns of codon assignments within the context of theoretical RNA structures.
- To explore the relationship between codon evolvability, RNA ring composition, and amino acid assignment.
- To uncover novel properties of the standard genetic code and RNA rings by applying alternative genetic codes.
Main Methods:
- In silico design of 25 minimal RNA rings to encode all standard genetic signals.
- Analysis of codon usage biases and their correlation with RNA ring structure and composition.
- Application of alternative genetic codes to assess the robustness and properties of the standard genetic code.
Main Results:
- Identified 15 'evolvable' codons (23.4% of 64) across 31 genetic codes, with biases in their distribution within RNA rings.
- Demonstrated a positive correlation between the number of evolvable codons, cytosine content, and recent amino acid cognates in RNA rings.
- Revealed that RNA rings with evolvable codons exhibit specific positional biases within their sequences.
Conclusions:
- Evolvable codons and cytosine content play significant roles in the evolution of genetic codes and RNA structures.
- The study highlights unsuspected properties of the standard genetic code and RNA rings, particularly concerning codon assignment evolvability.
- Findings suggest a deeper connection between genetic code structure, RNA composition, and evolutionary adaptability.
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