Contact Cluster Modeling of Allosteric Communication in PDZ Domains.

Area of Science:

• Protein dynamics
• Biomolecular regulation
• Allosteric mechanisms

Background:

• Allostery enables long-range communication in proteins, crucial for regulation and signal transduction.
• The dynamical basis of allostery, beyond conformational changes, is not fully understood.
• The contact cluster model offers a new framework for understanding allosteric pathways.

Purpose of the Study:

• To validate and generalize the contact cluster model of allostery.
• To investigate the role of contact clusters in protein dynamics and communication.
• To explore how protein structure, ligands, and perturbations affect allosteric mechanisms.

Main Methods:

• Utilized extensive molecular dynamics simulations (approximately 1 ms total).
• Analyzed four distinct photoswitchable PDZ domains.
• Examined the influence of varying domains, ligands, and perturbations on contact clusters.

Main Results:

• Identified recurring contact clusters, often involving loops connecting beta-sheets.
• Demonstrated that protein response timescales correlate with individual contact cluster dynamics.
• Revealed a modular, dynamics-based architecture facilitating allosteric communication.

Conclusions:

• The contact cluster model provides a robust framework for understanding allosteric communication.
• Protein allostery is mediated by dynamic interactions within and between contact clusters.
• This modular architecture is key to efficient long-range signaling in proteins.