Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

DNA Topoisomerases02:02

DNA Topoisomerases

Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types.  Type I...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
DNA Helicases00:55

DNA Helicases

DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Dynamic Regulation of Endogenous Transcription Factor Hubs at Single-Molecule Resolution.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)·2026
Same author

Bacterial type II topoisomerases cleave DNA in a species-specific manner.

Nucleic acids research·2026
Same author

Distinct repair outcomes from single and convergent replication fork collapse.

Nature structural & molecular biology·2026
Same author

Networked salt-bridges mediate magnesium-dependent conformational dynamics and functional regulation in type IA topoisomerases.

Nature communications·2026
Same author

Strand-independent degradation of uncoupled forks by EXO1 activates ATR and restrains synthesis.

bioRxiv : the preprint server for biology·2026
Same author

Tissue and CD4 T cell subset dependence on the amino acid transporter SLC38A1.

Cell metabolism·2026

Related Experiment Video

Updated: Jul 12, 2026

Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase
07:37

Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase

Published on: September 27, 2024

Topoisomerase IIIα resolves inter- and intra-molecular intertwines during DNA replication.

Sabrina X Van Ravenstein, Lillian V Campos, Gabor M Harami

    Biorxiv : the Preprint Server for Biology
    |July 10, 2026
    PubMed
    Summary

    Topoisomerase IIIα (TOP3α) is vital for genome integrity, especially when Topoisomerase IIα (TOP2α) is impaired. TOP3α resolves DNA linkages during replication termination and when single-stranded DNA levels rise, ensuring genome stability.

    More Related Videos

    Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae
    07:55

    Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae

    Published on: September 11, 2022

    Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
    10:12

    Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications

    Published on: April 21, 2023

    Related Experiment Videos

    Last Updated: Jul 12, 2026

    Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase
    07:37

    Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase

    Published on: September 27, 2024

    Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae
    07:55

    Detection of Homologous Recombination Intermediates via Proximity Ligation and Quantitative PCR in Saccharomyces cerevisiae

    Published on: September 11, 2022

    Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
    10:12

    Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications

    Published on: April 21, 2023

    Area of Science:

    • Molecular Biology
    • Genetics
    • Biochemistry

    Background:

    • Genome integrity relies on resolving topological stress.
    • Vertebrate topoisomerase IIα (TOP2α) resolves catenanes during DNA replication.
    • The role of Topoisomerase IIIα (TOP3α) in DNA replication is not fully understood.

    Purpose of the Study:

    • To investigate the role of TOP3α in DNA replication, particularly when TOP2α function is compromised.
    • To determine TOP3α's substrate specificity and binding partners during replication.

    Main Methods:

    • Utilized Xenopus egg extracts for in vitro DNA replication studies.
    • Assessed replication fork progression and daughter strand unlinking.
    • Investigated TOP3α activity independently of RMI1-RMI2 and BLM helicase.

    Main Results:

    • TOP3α promotes replication fork progression and daughter strand unlinking during replication termination.
    • TOP3α acts on lagging-strand single-stranded DNA (ssDNA) independently of known partners.
    • Elevated lagging-strand ssDNA leads to intramolecular ssDNA intertwines resolved by TOP3α.

    Conclusions:

    • TOP3α is essential for resolving DNA topological stress during replication termination.
    • TOP3α resolves both intermolecular and intramolecular DNA linkages, crucial for genome stability under various replication conditions.