Spatial elucidation of motion in proteins by ensemble-based structure calculation using exact NOEs

Area of Science:

• Biochemistry
• Structural Biology
• Biophysics

Background:

• Proteins are dynamic molecules with motions crucial for biomolecular functions.
• Understanding protein dynamics alongside structure is essential for detailed functional analysis.
• Existing methods offer insights into local dynamics, but detecting concerted motions remains challenging.

Purpose of the Study:

• To present an ensemble-based structure-determination protocol for analyzing protein dynamics.
• To detect and describe concerted motions within protein structures using experimental data.
• To apply the protocol to a model protein (GB3) and characterize its dynamic behavior.

Main Methods:

• Utilizing an ensemble-based structure-determination protocol.
• Employing ensemble-averaged distance restraints derived from exact Nuclear Overhauser Effect (NOE) rates.
• Applying the protocol to the model protein GB3 for validation.

Main Results:

• An ensemble of structures for the GB3 protein was successfully generated.
• Correlated motions across the β-sheet were identified.
• Concerted motions between the backbone and core side chains were revealed, alongside a lack of exchange between the β-sheet and α-helix.

Conclusions:

• The developed protocol effectively captures and describes complex protein dynamics.
• The findings highlight specific correlated and concerted motions critical for protein function.
• This approach provides a more comprehensive understanding of protein dynamics beyond static structures.