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Updated: Jan 17, 2026
11:27
Studying DNA Looping by Single-Molecule FRET
Published on: June 28, 2014
15.8K
Protein-mediated stabilization and nicking of the nontemplate DNA strand dramatically affect R-loop formation in
Ethan Holleman1, Thomas E Catley2, Tadas Sereiva1
1Department of Molecular and Cellular Biology, University of California, Davis, CA 95616.
Summary
Single-strand DNA binding proteins increase R-loop frequency by stabilizing nascent structures. DNA nicks, common lesions, also significantly boost R-loop formation, creating unique forked structures.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- R-loops are non-B DNA structures formed during transcription.
- Understanding R-loop dynamics is crucial for cellular regulation.
Purpose of the Study:
- Investigate the role of single-strand DNA binding proteins in R-loop formation.
- Determine the impact of DNA nicks on R-loop initiation and structure.
Main Methods:
- In vitro transcription with quantitative sequencing.
- Atomic force microscopy.
Main Results:
- Single-strand DNA binding proteins increased R-loop frequency 3-5 fold by stabilizing nascent R-loops.
- Nontemplate strand DNA nicks increased R-loop frequencies up to 100-fold.
- Nick-initiated R-loops exhibited unique forked structures with self-paired nontemplate strands.
Conclusions:
- R-loop formation is dynamic, influenced by stabilizing proteins.
- DNA nicks are potent initiators of a distinct R-loop class.
- Displaced single-stranded DNA is key to R-loop initiation and dynamics.
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