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Updated: Jun 21, 2026
09:52
Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging
Published on: January 31, 2019
Dynamics of nucleosomes revealed by time-lapse atomic force microscopy
Luda S Shlyakhtenko1, Alexander Y Lushnikov, Yuri L Lyubchenko
1Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, Nebraska 68198-6025, USA.
Biochemistry
|July 22, 2009
Summary
Nucleosome unwrapping, visualized by atomic force microscopy, reveals large DNA exposure from particle ends. This inherent dynamic process occurs without ATP-dependent remodeling proteins, offering new insights into chromatin regulation.
Area of Science:
- Molecular Biology
- Biophysics
- Genetics
Background:
- Chromatin dynamics regulate DNA accessibility, crucial for gene expression.
- Limited understanding of large-range nucleosome dynamics and DNA exposure mechanisms.
- Nucleosome opening and propagation mechanisms remain largely unknown.
Purpose of the Study:
- To directly visualize nucleosome dynamics and identify mechanisms of large-range DNA exposure.
- To investigate the inherent dynamics of nucleosomes in DNA unwrapping.
Main Methods:
- Single-molecule time-lapse atomic force microscopy (AFM) imaging.
- Direct visualization of nucleosome unwrapping processes.
Main Results:
- Observed nucleosome unwrapping initiating from particle ends, exposing large DNA regions (dozens of base pairs).
- Demonstrated complete nucleosome unfolding and histone core dissociation as a potential outcome.
- Unwrapping occurred independently of ATP-hydrolysis-dependent chromatin remodeling proteins.
Conclusions:
- Inherent nucleosome dynamics contribute significantly to chromatin unwrapping.
- Findings provide novel hypotheses for chromatin remodeling protein function and intracellular chromatin dynamics.
- Sheds new light on the molecular mechanisms governing nucleosome dynamics and DNA accessibility.
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