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Updated: May 21, 2025
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Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA
Published on: September 10, 2013
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Structure and dynamics of a nucleosome core particle based on Widom 603 DNA sequence
Grigoriy A Armeev1, Andrey V Moiseenko1, Nikita A Motorin1
1Department of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia.
Structure (London, England : 1993)
|March 18, 2025
Summary
This study reveals how DNA sequence influences nucleosome structure and dynamics. Researchers used cryo-electron microscopy to visualize nucleosomes, uncovering insights into DNA unwrapping mechanisms.
Area of Science:
- Structural Biology
- Molecular Biology
- Biophysics
Background:
- Nucleosomes are key to chromatin organization, DNA compaction, and protein binding.
- Over 500 nucleosome structures exist, but predominantly on limited DNA sequences.
- Understanding sequence-dependent nucleosome behavior is crucial for gene regulation.
Purpose of the Study:
- To determine the high-resolution structure of a nucleosome formed on the high-affinity Widom 603 DNA sequence.
- To investigate nucleosomal DNA unwrapping dynamics using an integrative modeling approach.
- To elucidate the impact of specific DNA sequences on nucleosome structure and dynamics.
Main Methods:
- Cryo-electron microscopy (cryo-EM) for high-resolution structure determination (4 Å resolution).
- Integrative modeling to study DNA unwrapping.
- Small-angle X-ray scattering (SAXS) and single-particle Förster resonance energy transfer (spFRET) for dynamic measurements.
Main Results:
- An atomic model of the Widom 603 nucleosome was successfully built.
- Cryo-EM data, combined with SAXS and spFRET, demonstrated asymmetric DNA unwrapping.
- Evidence was found for sequence-dependent modulation of nucleosome structure and dynamics.
Conclusions:
- The DNA sequence of nucleosomal DNA significantly impacts its structure and dynamic properties.
- The Widom 603 nucleosome exhibits asymmetric DNA unwrapping, providing insights into chromatin accessibility.
- Integrative modeling combined with experimental data offers a powerful approach to study nucleosome dynamics.
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