AI-Guided Conformational Dynamics of p53 L1 Loop Reveal an Allosteric Switch Regulating DNA Binding and Cancer...

Area of Science:

• Molecular Biology
• Biophysics
• Computational Biology

Background:

• The tumor suppressor p53 is crucial for cellular stress response and transcription regulation.
• Mutations in p53's DNA-binding domain (DBD) are common in human cancers.
• The L1 loop in the p53 DBD is vital for DNA recognition, but its dynamics are unclear.

Purpose of the Study:

• To elucidate the conformational dynamics of the p53 DBD L1 loop.
• To uncover the mechanism governing p53's DNA-binding activity.
• To provide insights into cancer-associated p53 mutations and therapeutic strategies.

Main Methods:

• Enhanced molecular dynamics simulations.
• Machine learning-derived collective variables for analyzing conformational changes.
• Identification of transition pathways and hydrogen bond networks.

Main Results:

• A novel conformational switch mechanism for p53 DNA binding was identified.
• Two distinct transition pathways between extended and recessed conformations were characterized.
• A potential allosteric mechanism regulating the DNA-p53 interface was discovered, explaining R282 mutations.
• A rationale for therapeutic compounds targeting the L1 loop reactivation pocket was proposed.

Conclusions:

• The study reveals a conformational switch mechanism controlling p53 DNA binding.
• This mechanism provides insights into cancer mutations and suggests therapeutic strategies targeting DNA binding kinetics.