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Updated: May 16, 2026
06:24
Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51
Published on: February 13, 2019
Probing Rad51-DNA interactions by changing DNA twist.
Scott Atwell1, Ludovic Disseau, Alicja Z Stasiak
1Institut Curie, Centre de Recherche-Physico-Chimie-Curie, CNRS UMR168, Université Pierre et Marie Curie, Paris F-75231, France.
Nucleic Acids Research
|November 28, 2012
Summary
Rad51 protein
Area of Science:
- Molecular Biology
- Biochemistry
- Genetics
Background:
- Rad51 protein is crucial for eukaryotic DNA repair, assembling nucleoprotein filaments on broken DNA ends.
- This process facilitates homologous pairing for error-free repair of double-strand breaks.
- The precise role of Rad51's ATPase activity in DNA repair remains unclear.
Purpose of the Study:
- To investigate how DNA twist influences Rad51-DNA complex structure.
- To elucidate the role of ATP hydrolysis in Rad51-mediated DNA repair.
- To understand the mechanism of homologous pairing and strand exchange.
Main Methods:
- Magnetic tweezers and electron microscopy were employed.
- Enforced changes in DNA twist were used to study Rad51-DNA interactions.
- The study analyzed the structural transitions of Rad51-DNA complexes.
Main Results:
- Rad51 binds double-stranded DNA in two distinct modes based on DNA twist: a stretching mode (18.6 bp/turn) and a non-stretching mode (native helical repeat).
- These two complex forms are interconvertible, with DNA twist changes inducing transitions between them.
- ATP hydrolysis's role in Rad51's function was further clarified through these structural insights.
Conclusions:
- DNA twist significantly impacts Rad51-DNA complex formation and stability.
- Interconversion between Rad51-DNA complex forms is regulated by DNA twist.
- This research provides a deeper understanding of ATP hydrolysis in Rad51-mediated DNA repair and strand exchange.
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