Solitons and collapse in the λ-repressor protein

Area of Science:

• Molecular Biology
• Biophysics
• Structural Biology

Background:

• The lambda phage repressor protein (CI) regulates lysogenic and lytic cycles.
• Understanding CI protein structure and folding is crucial for phage biology.

Purpose of the Study:

• To investigate the structure, stability, and folding pathways of the lambda phage repressor protein.
• To model the protein's helix-loop helix composition and folding dynamics.

Main Methods:

• Discrete Frenet framing to analyze backbone structure.
• Soliton Ansatz modeling for loop structures.
• Coarse-grained energy function for folding dynamics simulation.

Main Results:

• Identified seven distinct loops in the repressor's backbone structure.
• Folding dynamics are governed by the temporal order of soliton formation.
• The third soliton's formation is critical for the DNA binding turn structure.

Conclusions:

• The lambda repressor's folding pathway is dominated by specific soliton formation sequences.
• The folded state is stable and achievable from various initial configurations.
• This research provides insights into bacteriophage regulatory protein dynamics.