Coevolution of RNase P and the ribosome

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Structural Biology

Background:

• The ribosome and RNase P are highly conserved ribonucleoprotein complexes essential for biological processes.
• These complexes were structurally and functionally mature by the time of the last universal common ancestor (LUCA).
• Previous work reconstructed ribosome evolution using a 3D structure-based accretion model.

Purpose of the Study:

• To extend the accretion model framework to reconstruct the evolutionary history of RNase P RNA (RPR).
• To characterize the structure of RPR at LUCA and determine its emergence chronology.
• To investigate the coevolution of RPR and ribosomal RNA (rRNA) in relation to tRNA interactions.

Main Methods:

• Phylogenetic sampling of RPR sequences and structures.
• Partitioning RPR into fragments based on insertion fingerprints to trace evolutionary accretion.
• Utilizing tRNA interaction data to link RPR and rRNA evolutionary trajectories.
• Applying an accretion model based on structural phylogenetics.

Main Results:

• RNase P, similar to the ribosome, evolved through the accretion of modular RNA elements.
• The structure of RPR at LUCA was characterized, and its emergence chronology was reconstructed.
• Evidence suggests RPR and rRNA share common ancestry in some accreted elements.
• The ancestral catalytic sites of both RPR and rRNA likely formed via fusion of stem-elbow-stem elements.
• Successful application of the accretion model required correcting traditional RPR secondary structures, including pseudoknots.

Conclusions:

• RNase P and the ribosome likely coevolved as an integrated functional system.
• The accretion model provides a framework for understanding the evolution of ancient ribonucleoprotein complexes.
• The structural record preserved within RPR and rRNA reflects their evolutionary accretion.
• The findings support a model where fundamental biological machinery evolved through modular assembly.