How does symmetry impact the flexibility of proteins?

Area of Science:

• Structural biology
• Biophysics
• Computational biology

Background:

• Protein flexibility and rigidity are fundamental to protein function.
• Oligomeric proteins assemble with symmetry, and symmetry can enhance structural flexibility.
• The theory of generic rigidity in body-bar frameworks provides tools to analyze molecular structures.

Purpose of the Study:

• Investigate the coincidence between common protein oligomer symmetry classes and increased structural flexibility.
• Explore the functional significance of symmetry-induced flexibility in proteins.
• Develop methods to predict symmetry-preserving motions in protein structures.

Main Methods:

• Utilizing the theory of generic rigidity for body-bar frameworks.
• Applying fast combinatorial algorithms for rigidity and flexibility analysis.
• Developing simple counting rules and algorithmic extensions for predicting motions.

Main Results:

• Identified that prevalent symmetry classes in protein oligomers are associated with enhanced flexibility.
• Demonstrated a link between symmetry and flexibility in three-dimensional protein structures.
• Focused analysis on dimers, highlighting their common twofold rotational symmetry and its implications.

Conclusions:

• The observed correlation between common symmetry classes and protein flexibility is significant.
• Symmetry plays a key role in enabling functional motions, particularly in allosteric regulation of dimers.
• The developed methods offer a way to predict continuous, symmetry-preserving motions in proteins.