A parameterized two-domain thermodynamic model explains diverse mutational effects on protein allostery

Area of Science:

• Molecular Biology
• Biophysics
• Protein Dynamics

Background:

• Allosteric regulation is crucial for protein function.
• Traditional models assume allosteric effects travel along defined structural pathways.
• Recent studies challenge this, showing broadly distributed allosteric hotspots.

Purpose of the Study:

• To develop a thermodynamic model for the tetracycline repressor (TetR) to explain observed allosteric behaviors.
• To quantify the effects of mutations on protein allostery using statistical inference.
• To investigate the relationship between intra- and inter-domain properties in allosteric regulation.

Main Methods:

• Development of a two-domain thermodynamic model for TetR.
• Analysis of deep mutational scanning data.
• Application of statistical inference for parameter quantification.

Main Results:

• The model successfully rationalizes experimental findings on broadly distributed allosteric hotspots.
• Mutation effects were quantified using physically transparent parameters.
• Intra- and inter-domain connections governing allostery and epistasis were revealed.

Conclusions:

• Allosteric regulation in TetR involves interconnected intra- and inter-domain properties.
• The findings challenge conventional views of allosteric pathways.
• The model provides a framework for understanding multi-domain allosteric proteins.