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Updated: Jul 25, 2026
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Atomic Force Microscopy Investigations of DNA Lesion Recognition in Nucleotide Excision Repair
Published on: May 24, 2017
Structure and dynamics of three-way DNA junctions: atomic force microscopy studies.
L S Shlyakhtenko1, V N Potaman, R R Sinden
1Department of Microbiology and Department of Biology, Arizona State University, Tempe, AZ 85287-2701, USA.
Nucleic Acids Research
|September 13, 2000
Summary
Atomic force microscopy reveals DNA replication intermediates are dynamic and non-flat. These three-way DNA junctions exhibit significant mobility and a pyramid-like structure, not a flat conformation.
Area of Science:
- Molecular Biology
- Biophysics
- Structural Biology
Background:
- Three-way DNA junctions are critical intermediates in DNA replication and recombination.
- Understanding their structure is key to deciphering these fundamental genetic processes.
Purpose of the Study:
- To investigate the three-dimensional conformation and dynamics of three-way DNA junctions.
- To characterize the structural features of these DNA structures using advanced microscopy.
Main Methods:
- Atomic Force Microscopy (AFM) was employed to visualize DNA structures.
- Immobile three-way junctions were synthesized by annealing DNA fragments.
- AFM imaging was performed on both dried samples and in liquid (in situ).
Main Results:
- AFM analysis clearly identified three-armed DNA molecules with distinct arm lengths.
- Three-way DNA junctions demonstrated significant structural dynamics and mobility.
- Measurements indicated that these junctions possess a non-flat, pyramid-like conformation.
Conclusions:
- Three-way DNA junctions are highly dynamic structures, not static entities.
- The non-planar, pyramid-like geometry of these junctions is a crucial structural characteristic.
- These findings necessitate consideration of junctional non-flatness in AFM data interpretation.
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