ArticleProceedings of the National Academy of Sciences of the United States of America2002
Preferential cleavage of plasmid-based R-loops and D-loops by Drosophila topoisomerase IIIbeta.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2002. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers.
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Who cites it
24 citing papers in PubMed, 38 citations in OpenAlex.
- Genome-wide mapping reveals increased R-loops in topoisomerase III-beta-deficient human cells.iScience · 2026Article
- R-Loops in Genome Instability and Cancer.Cancers · 2023Review
- Review
- Resolution of R-loops by topoisomerase III-β (TOP3B) in coordination with the DEAD-box helicase DDX5.Cell reports · 2022Article
- DNA and RNA Cleavage Complexes and Repair Pathway for TOP3B RNA- and DNA-Protein Crosslinks.Cell reports · 2020Article
- The many lives of type IA topoisomerases.The Journal of biological chemistry · 2020Review
- Emerging roles for R-loop structures in the management of topological stress.The Journal of biological chemistry · 2020Review
- Loss of TOP3B leads to increased R-loop formation and genome instability.Open biology · 2019Article
- Born to run: control of transcription elongation by RNA polymerase II.Nature reviews. Molecular cell biology · 2018Review
- RNA-DNA hybrid (R-loop) immunoprecipitation mapping: an analytical workflow to evaluate inherent biases.Genome research · 2017Article
- Topoisomerase 3β is the major topoisomerase for mRNAs and linked to neurodevelopment and mental dysfunction.Nucleic acids research · 2017Article
- Structural basis of the interaction between Topoisomerase IIIβ and the TDRD3 auxiliary factor.Scientific reports · 2017Article
- Roles of eukaryotic topoisomerases in transcription, replication and genomic stability.Nature reviews. Molecular cell biology · 2016Review
- DNA and RNA topoisomerase activities of Top3β are promoted by mediator protein Tudor domain-containing protein 3.Proceedings of the National Academy of Sciences of the United States of America · 2016Article
- Structural and dynamic views of the CRISPR-Cas system at the single-molecule level.BMB reports · 2016Review
- Structural basis for suppression of hypernegative DNA supercoiling by E. coli topoisomerase I.Nucleic acids research · 2015Article
- R loops: new modulators of genome dynamics and function.Nature reviews. Genetics · 2015Review
- Top3-Rmi1 dissolve Rad51-mediated D loops by a topoisomerase-based mechanism.Molecular cell · 2015Article
- Readers of histone methylarginine marks.Biochimica et biophysica acta · 2014Review
- Arginine methylation facilitates the recruitment of TOP3B to chromatin to prevent R loop accumulation.Molecular cell · 2014Article
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Authors and funding
2 authors at 1 institution in 1 country.
Funding
Abstract
The topoisomerase (topo) III enzymes are found in organisms ranging from bacteria to humans, yet the precise cellular function of these enzymes remains to be determined. We previously found that Drosophila topo IIIbeta can relax plasmid DNA only if the DNA is first hypernegatively supercoiled. To investigate the possibility that topo IIIbeta requires a single-stranded region for its relaxation activity, we formed R-loops and D-loops in plasmids. In addition to containing a single-stranded region, these R-loops and D-loops have the advantage of being covalently closed and supercoiled, thus allowing us to assay for supercoil relaxation. We found that topo IIIbeta preferentially cleaves, rather than relaxes, these substrates. The cleavage of the R-loops and D-loops, which is primarily in the form of nicking, occurs to a greater extent at a temperature that is lower than the optimal temperature for relaxation of hypernegatively supercoiled plasmid. In addition, the cleavage can be readily reversed by high salt or high temperature, and the products fail to enter the gel in the absence of proteinase K treatment and are not observed with an active-site Y332F mutant of topo IIIbeta, indicating that the cleavage is mediated by a topoisomerase. We mapped the cleavage to the unpaired strand within the loop region and found that the cleavage occurs along the length of the unpaired strand. These studies suggest that the topo III enzyme behaves as a structure-specific endonuclease in vivo, providing a reversible DNA cleavage activity that is specific for unpaired regions in the DNA.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.