Parallel molecular mechanisms for enzyme temperature adaptation.

Area of Science:

• Molecular Evolution
• Enzymology
• Biophysics

Background:

• Understanding enzyme adaptation to temperature is key to molecular evolution.
• Enzymes must maintain activity and stability across different temperatures.
• Evolutionary strategies for temperature adaptation are diverse.

Purpose of the Study:

• Investigate molecular and evolutionary mechanisms of enzyme temperature adaptation.
• Combine mechanistic studies with large-scale sequence analysis.
• Identify key residues and evolutionary patterns in temperature adaptation.

Main Methods:

• Deep mechanistic studies of ketosteroid isomerase (KSI).
• Comprehensive sequence analyses of thousands of bacterial enzymes.
• Assessment of residue properties, molecular interactions, and networks.

Main Results:

• Temperature adaptation in KSI is driven by a single residue change with minimal epistasis.
• This adaptation mechanism is observed across diverse KSI backgrounds, indicating parallel evolution.
• Identified residues linked to organismal growth temperature in 1005 bacterial enzyme families, suggesting widespread parallel adaptation.

Conclusions:

• Single residue changes are significant drivers of enzyme temperature adaptation.
• Parallel evolution is a common strategy for bacterial enzymes adapting to temperature.
• Specific residue properties and interactions underpin temperature adaptation.