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Updated: Jul 28, 2026
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Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
Intermolecular interactions and water structure in a condensed phase B-DNA crystal
G R Clark1, C J Squire, L J Baker
1Chemistry Department, University of Auckland, Auckland, New Zealand.
Nucleic Acids Research
|February 10, 2000
Summary
Controlled dehydration of DNA-drug crystals significantly reduced unit cell volume, enhancing X-ray diffraction resolution. This revealed a tightly packed B-form DNA structure crosslinked by magnesium ions.
Area of Science:
- Structural Biology
- Biophysics
- Crystallography
Background:
- DNA-drug crystals exhibit complex structures influenced by hydration.
- Understanding DNA condensation is crucial for molecular biology and drug design.
Purpose of the Study:
- To investigate the structural changes in dodecamer DNA-drug crystals upon controlled dehydration.
- To determine the high-resolution structure of fully dehydrated B-form DNA.
Main Methods:
- Controlled dehydration of DNA-drug crystals.
- X-ray diffraction data collection and structure determination.
- Refinement of crystal structures to high resolution.
Main Results:
- Unit cell volume reduced from 68,000 ų to 51,000 ų upon dehydration.
- X-ray diffraction resolution improved from 2.6 Å to beyond 1.5 Å.
- A highly ordered, tightly packed B-form DNA structure crosslinked by magnesium cations was elucidated.
Conclusions:
- Dehydration induces significant structural changes and enhances DNA packing.
- The fully dehydrated state reveals a polymeric network of DNA stabilized by magnesium bridges.
- This study provides a reliable model for condensed B-form DNA.
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