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Identifying and Overcoming Crystal Pathologies: Disorder and Twinning
1Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, Box 2240, 600 16th Street, S476, San Francisco, CA, 94158, USA. michael.thompson2@ucsf.edu.
Methods in Molecular Biology (Clifton, N.J.)
|June 3, 2017
Summary
Macromolecular crystals can develop pathologies like rigid-body disorder and twinning, complicating structure determination. This chapter guides researchers in identifying and overcoming these crystal defects for successful analysis.
Area of Science:
- Crystallography
- Structural Biology
- Biophysics
Background:
- Macromolecular crystals are essential for determining 3D structures of biological molecules.
- Aberrant molecular packing can lead to crystal pathologies, affecting diffraction data quality.
- Rigid-body disorder and twinning are common issues that complicate structure determination.
Purpose of the Study:
- To introduce common pathologies in macromolecular crystals: rigid-body disorder and twinning.
- To explain how these pathologies alter diffraction patterns.
- To provide guidelines for identifying and overcoming these issues in structure determination.
Main Methods:
- Review of crystallographic principles related to molecular packing.
- Analysis of diffraction data alterations caused by disorder and twinning.
- Case studies illustrating identification and resolution strategies.
Main Results:
- Pathologies like rigid-body disorder and twinning significantly impact diffraction patterns.
- The severity of impact varies, sometimes being subtle and other times obvious.
- Successful structure determination is possible but depends on pathology type and data handling.
Conclusions:
- Understanding and identifying crystal pathologies are crucial for accurate structure determination.
- Guidelines are provided to help researchers overcome challenges posed by disorder and twinning.
- Proactive management of these issues enhances the success rate of structural studies.
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