Integrative Modeling of Biomolecular Complexes: HADDOCKing with Cryo-Electron Microscopy Data

Area of Science:

• Structural Biology
• Biophysics
• Computational Biology

Background:

• Protein-protein interactions are crucial for cellular functions.
• Cryo-electron microscopy (cryo-EM) images large molecular complexes but often lacks atomic resolution.
• Existing methods for integrating cryo-EM data with atomic structures have limitations.

Purpose of the Study:

• To develop and validate a computational approach for integrating cryo-electron microscopy (cryo-EM) data into protein complex modeling.
• To improve the accuracy of atomic models for protein-protein interactions by combining cryo-EM data with other experimental information.
• To reveal novel details of molecular interactions through enhanced structural modeling.

Main Methods:

• Integration of cryo-electron microscopy (cryo-EM) data into the HADDOCK (High Ambiguity Driven protein-DOCKing) program.
• Benchmarking the approach on 17 protein complexes.
• Demonstration on five systems using cryo-EM data (8.5–21 Å resolution).
• Incorporation of additional experimental data, such as mutagenesis and hydroxyl radical footprinting.

Main Results:

• The integrated approach successfully modeled protein complexes using cryo-EM data.
• The resulting models exhibit high-quality interfaces.
• Novel details of protein-protein interactions were revealed.
• Performance was validated on a benchmark set of complexes.

Conclusions:

• The integration of cryo-EM data into HADDOCK significantly enhances the accuracy of protein complex structural models.
• This approach overcomes resolution limitations of cryo-EM by combining it with computational modeling and other experimental data.
• The method provides valuable insights into the atomic architecture of protein-protein interactions.