REDCRAFT: A computational platform using residual dipolar coupling NMR data for determining structures of...

Area of Science:

• Biophysics
• Structural Biology
• Nuclear Magnetic Resonance (NMR) Spectroscopy

Background:

• Nuclear Magnetic Resonance (NMR) spectroscopy is a key technique for characterizing macromolecular structures, especially proteins.
• Traditional protein structure determination relies heavily on Nuclear Overhauser Effect (NOE) measurements for distance restraints.
• Structure determination using Residual Dipolar Couplings (RDCs) is less developed compared to NOE-based methods.

Purpose of the Study:

• To introduce and evaluate new features in the REDCRAFT protein structure modeling program.
• To highlight the Adaptive Decimation (AD) feature for improved robustness and efficiency in RDC-based structure determination.
• To demonstrate the capability of REDCRAFT for determining protein structures using RDC data alone.

Main Methods:

• Utilized the REDCRAFT program incorporating the novel Adaptive Decimation (AD) feature.
• Applied REDCRAFT to experimentally collected RDC data for proteins of 50-145 residues.
• Used simulated RDC data for larger proteins (145-573 residues) from perdeuterated samples.
• Compared RDC-only structure determination accuracy against traditional NOE-based methods for a novel protein.

Main Results:

• REDCRAFT demonstrated robustness to missing or noisy RDC data, enabling structure determination of larger proteins.
• Successful structure determination was achieved for proteins using experimentally collected and simulated RDC data.
• The RDC-based structure of the PF.2048.1 protein showed high accuracy (1.0 Å BB-RMSD) compared to an NOE-based structure.
• Proof-of-principle for robust structure determination of perdeuterated proteins using RDC data alone was established.

Conclusions:

• The REDCRAFT program, particularly with its Adaptive Decimation feature, significantly enhances RDC-based protein structure determination.
• This approach allows for robust structure determination of larger proteins, even with limited or imperfect RDC data.
• While combining RDC data with other NMR restraints is optimal, RDC data alone provides a viable and accurate method for structural characterization.