Analysis of codon usage pattern in the radioresistant bacterium Deinococcus radiodurans.

Area of Science:

• Genomics
• Molecular Biology
• Bioinformatics

Background:

• Codon usage bias significantly influences gene expression and protein synthesis.
• Understanding factors driving codon bias is crucial for deciphering genome evolution and optimizing genetic engineering.

Purpose of the Study:

• To identify and analyze the key factors contributing to synonymous codon usage bias in the Deinococcus radiodurans genome.
• To investigate the relative importance of gene expression, nucleotide composition, CDS length, and protein hydrophobicity in shaping codon usage patterns.

Main Methods:

• Correspondence Analysis (COA) was employed to analyze synonymous codon usage patterns.
• Correlation analysis, variance analysis, and neutrality plots were used to assess contributing factors.
• Codon Adaptation Index (CAI) was utilized to evaluate gene expression levels.

Main Results:

• Gene expression level, assessed by CAI, was the dominant factor correlated with codon usage bias.
• Nucleotide composition, CDS length, and protein hydrophobicity showed minor but significant contributions to codon bias.
• A trend indicated longer CDS genes with higher expression levels exhibited more biased codon usage.

Conclusions:

• Gene expression level is the most critical determinant of codon usage bias in D. radiodurans.
• Nucleotide mutational bias, CDS length, and protein hydrophobicity play secondary roles.
• The identification of 19 "optimal codons" offers potential applications in molecular genetic engineering and evolutionary studies.