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Probing The Structure And Dynamics Of Nucleosomes Using Atomic Force Microscopy Imaging
Published on: January 31, 2019
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Dynamics of nucleosomal structures measured by high-speed atomic force microscopy
Allard J Katan1, Rifka Vlijm, Alexandra Lusser
1Bionanoscience Department, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628, CJ, The Netherlands.
Small (Weinheim an Der Bergstrasse, Germany)
|October 23, 2014
Summary
Nucleosomes and tetrasomes exhibit dynamic behaviors, including spontaneous disassembly and stable DNA loop formation. High-speed atomic force microscopy reveals tetrasome dynamics crucial for understanding DNA accessibility during transcription.
Area of Science:
- Structural biology
- Molecular dynamics
- Biophysics
Background:
- Nucleosome accessibility impacts DNA-related cellular processes.
- Nucleosomes (8 histones) and tetrasomes (4 histones) are key DNA-packaging structures.
- Understanding their dynamics is vital for gene regulation.
Purpose of the Study:
- To visualize and characterize the dynamic processes of nucleosomes and tetrasomes.
- To investigate tetrasome dynamics during disassembly and on DNA.
- To demonstrate the utility of high-speed AFM in studying protein-DNA interactions.
Main Methods:
- High-speed atomic force microscopy (HS-AFM) for real-time visualization.
- Observation of nucleosome and tetrasome structural dynamics.
- Analysis of disassembly, DNA looping, sliding, and hopping phenomena.
Main Results:
- Nucleosomes disassemble spontaneously on a second timescale.
- Tetrasomes exhibit stable DNA loop formation (minutes) during disassembly.
- Intact tetrasomes show dynamic sliding and reversible hopping along DNA.
- Tetrasomes are highly dynamic, not static structures.
Conclusions:
- Tetrasome dynamics are significant for understanding DNA accessibility during transcription.
- HS-AFM is effective for characterizing dynamic protein-DNA interactions.
- Reveals the diverse dynamics of nucleosome-related structures.
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