On the complementarity of X-ray and NMR data

Area of Science:

• Structural Biology
• Biophysics
• Computational Biology

Background:

• X-ray crystallography and Nuclear Magnetic Resonance (NMR) provide complementary structural information for biological macromolecules.
• X-ray diffraction is sensitive to overall molecular shape, while NMR provides atomic-level detail.
• Combining these techniques can strengthen the validation of determined structures.

Purpose of the Study:

• To describe an integrative approach for refining X-ray structures using NMR data.
• To investigate the extent of complementarity between X-ray crystallography and NMR.
• To assess the impact of different crystal forms on integrative refinement outcomes.

Main Methods:

• Utilized REFMAC-NMR, a method for joint refinement using primary data from both X-ray diffraction and NMR.
• Applied an integrative approach to refine four X-ray crystal structures of hen-egg-white lysozyme.
• Solved structures at atomic resolution in four distinct crystal forms.

Main Results:

• Demonstrated that integrative refinement with NMR data is feasible.
• Showcased that the success of NMR data integration is critically dependent on the crystal form.
• Highlighted NMR's sensitivity to fine structural details influenced by the crystalline environment.

Conclusions:

• The integration of X-ray crystallography and NMR data offers a powerful approach for structural characterization.
• Crystal form significantly influences the outcome of integrative refinement, underscoring the importance of crystal packing effects.
• Further exploration of integrative methods can enhance the accuracy and reliability of structural models for biological macromolecules.