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Updated: Aug 12, 2025
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Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
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Structure of a 28.5 kDa duplex-embedded G-quadruplex system resolved to 7.4 Å resolution with cryo-EM
Robert C Monsen1, Eugene Y D Chua2, Jesse B Hopkins3
1UofL Health Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA.
Nucleic Acids Research
|January 30, 2023
Summary
Genomic G-quadruplexes (G4s) in duplex DNA structures exhibit significant bending and druggability. Integrated structural methods reveal dynamic insights into these important transcriptional regulators.
Area of Science:
- Structural Biology
- Genomics
- Biophysics
Background:
- Guanine-rich genomic regions form G-quadruplexes (G4s), known transcriptional regulators.
- Limited structural data exists for G4s within their native duplex DNA context.
Purpose of the Study:
- To determine the structure and dynamics of a duplex-G4-duplex (DGD) model system.
- To assess the druggability of G4 structures within a duplex environment.
Main Methods:
- Cryo-electron microscopy (cryo-EM) at 7.4 Å resolution.
- Molecular dynamics (MD) simulations.
- Small-angle X-ray scattering (SAXS) studies.
Main Results:
- The DGD model exhibits a 53° bend due to stacked duplex-G4 interactions.
- A poly dT loop preferentially stacks, occluding G4 interfaces.
- The DGD model shows increased druggability compared to monomeric G4s.
Conclusions:
- Integrated structural methods provide detailed static and dynamic information on DNA G4 systems.
- The DGD model represents a novel drug target with enhanced druggability.
- Understanding G4 structures in duplex DNA is crucial for their role in gene regulation.
