Codon usage bias from tRNA's point of view: redundancy, specialization, and efficient decoding for translation...

Area of Science:

• Molecular Evolution
• Genomics
• Biochemistry

Background:

• The selection-mutation-drift theory explains codon usage bias and transfer RNA (tRNA) content co-evolution for translation optimization.
• Previous research primarily focused on codon usage, neglecting the role of the tRNA gene pool.

Purpose of the Study:

• To analyze the tRNA gene pool across 102 bacterial species.
• To investigate the relationship between minimal generation times, tRNA gene numbers, anticodon species, and codon usage bias.
• To understand the selective forces driving translation machinery optimization.

Main Methods:

• Analysis of tRNA gene pools in 102 bacterial species.
• Comparative genomic analysis of tRNA gene composition and codon usage bias.
• Testing three models to explain codon-anticodon recognition.

Main Results:

• Bacterial genomes with shorter minimal generation times have more tRNA genes but fewer anticodon species.
• Despite G+C content variation, anticodon composition is conserved across most bacterial genomes.
• Highly expressed genes in fast-growing bacteria exhibit codon usage bias towards codons matching frequent anticodons.

Conclusions:

• The co-evolution of tRNA gene composition and codon usage bias aligns with the selection-mutation-drift theory.
• A conserved trend in anticodon and codon choice evolution suggests a universal optimization strategy.
• Maximization of growth is a significant selective force for optimizing the translation machinery.