Kullback Leibler divergence in complete bacterial and phage genomes

Area of Science:

• Genomics
• Bioinformatics
• Microbial Ecology

Background:

• The amino acid composition of proteins can indicate an organism's lifestyle and genomic coding potential.
• Understanding these patterns is crucial for analyzing complex biological systems.

Purpose of the Study:

• To analyze amino acid utilization profiles across bacterial and phage genomes.
• To identify correlations between amino acid composition, phylogeny, lifestyle, and genomic features like GC content.
• To explore the potential application of these findings in distinguishing coding from non-coding sequences.

Main Methods:

• Calculation of Kullback-Leibler divergence to quantify amino acid composition differences.
• Comparative analysis of amino acid profiles in large datasets of bacterial and phage genomes.
• Correlation analysis with genomic GC content and investigation of lifestyle associations (e.g., endosymbionts, parasites).

Main Results:

• Significant differences in amino acid utilization exist across bacterial and phage phylogenetic groups.
• Skewed amino acid profiles are prevalent in endosymbiotic or parasitic bacteria and their phages.
• Amino acid skews are widespread across bacterial genomic subsystems, not limited to specific metabolic pathways.
• Amino acid profiles correlate strongly with bacterial genome GC content but weakly with phage GC content.

Conclusions:

• Amino acid composition provides insights into bacterial and phage biology, including lifestyle adaptations.
• The observed patterns can potentially aid in the computational identification of coding sequences within genomic data, particularly in metagenomic libraries.