Walking from E. coli to B. subtilis, one ribonuclease at a time

Area of Science:

• Microbiology
• Evolutionary Biology
• Molecular Biology

Background:

• Bacterial ribonucleases (RNases) are crucial for RNA processing and degradation.
• Known RNases are primarily studied in Escherichia coli and Bacillus subtilis, which are phylogenetically distant.
• These organisms exhibit significant differences in their RNA maturation and degradation machineries.

Purpose of the Study:

• To elucidate the functions of major RNases in Escherichia coli and Bacillus subtilis.
• To describe the evolutionary divergence of RNase repertoires between these two bacteria.
• To characterize the gradients of enzyme presence and absence across the bacterial phylogenetic spectrum.

Main Methods:

• Comparative analysis of known RNase functions in E. coli and B. subtilis.
• Phylogenetic analysis to understand enzyme evolution.
• Description of enzyme 'fading in' and 'fading out' across evolutionary distances.

Main Results:

• E. coli and B. subtilis possess distinct sets of RNases, with limited overlap.
• A core set of RNases is conserved across the bacterial spectrum.
• Evolutionary gradients illustrate the divergence and convergence of RNase functions between the two species.

Conclusions:

• The RNA processing and degradation pathways in bacteria are shaped by significant evolutionary divergence.
• Understanding RNase functions in disparate bacteria like E. coli and B. subtilis provides insights into bacterial RNA metabolism evolution.
• RNase repertoires can be described by opposing evolutionary gradients from E. coli to B. subtilis.