CryoROLE: describing large inter-domain rotation in single particle cryo-EM.

Area of Science:

• Structural biology
• Computational biology
• Biophysics

Background:

• Analyzing continuous conformational heterogeneity in single particle cryo-electron microscopy (cryo-EM) remains a significant challenge.
• Existing methods, including linear and deep learning approaches, often simplify complex protein motions as minor deviations from an average structure, limiting their ability to capture large-scale domain movements.
• Traditional classification methods discretize continuous dynamics into static substates, failing to represent the fluid nature of protein motion.

Purpose of the Study:

• To introduce cryoROLE, a novel computational tool designed to extract and visualize continuous conformational dynamics from cryo-EM data.
• To enable intuitive interpretation of large-scale domain motions and their associated conformational populations in protein structures.
• To uncover functionally relevant conformational dynamics previously hidden in composite cryo-EM maps.

Main Methods:

• Development of cryoROLE, a computational tool leveraging multi-body refinement.
• Extraction of continuous conformational dynamics as a landscape of relative domain orientations.
• Real-space visualization of protein conformational landscapes and pose populations.

Main Results:

• cryoROLE successfully extracts continuous conformational dynamics from static composite maps generated by multi-body refinement.
• The tool provides an intuitive, real-space landscape for interpreting domain motion and conformational space populations.
• Application to diverse biological systems revealed previously undetected conformational dynamics linked to protein functions.

Conclusions:

• cryoROLE offers a powerful new approach for analyzing continuous conformational heterogeneity in cryo-EM.
• The tool facilitates a deeper understanding of protein dynamics and their functional implications.
• cryoROLE enhances the interpretability of cryo-EM data, particularly for systems exhibiting large-scale conformational changes.