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 Helicases00:55

DNA Helicases

24.8K
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...
24.8K
Single-Strand DNA Binding Proteins01:03

Single-Strand DNA Binding Proteins

17.1K
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
17.1K
DNA Topoisomerases02:02

DNA Topoisomerases

37.2K
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. ...
37.2K
Homologous Recombination02:31

Homologous Recombination

65.1K
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...
65.1K

You might also read

Related Articles

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

Sort by
Same author

Dynamic Assemblies in Genome Maintenance.

Advances in experimental medicine and biology·2026
Same author

Human REV1 interacts with DHX36 to promote replication and tolerance of G-quadruplex DNA.

Nucleic acids research·2026
Same author

Base-pair scale dynamics of a repair helicase on DNA lesions reveal varied damage-sensing mechanisms.

bioRxiv : the preprint server for biology·2026
Same author

Discovery of a pyridine-piperazine-based small molecule that enhances the activity of peptidase neurolysin.

The Journal of pharmacology and experimental therapeutics·2026
Same author

The human RAD52 complex undergoes phase separation and facilitates bundling and end-to-end tethering of RAD51 presynaptic filaments.

Nucleic acids research·2026
Same author

Introducing <i>NAR Molecular Medicine</i>, a new journal in the <i>Nucleic Acids Research</i> family.

NAR molecular medicine·2025

Related Experiment Video

Updated: Mar 20, 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

2.6K

Single-molecule sorting of DNA helicases.

Fletcher E Bain1, Colin G Wu1, Maria Spies1

  • 1Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA, USA.

Methods (San Diego, Calif.)
|May 26, 2016
PubMed
Summary

Single-molecule sorting enables the study of human DNA helicase activity and post-translational modifications. This method quantifies and distinguishes modified and unmodified enzyme functions simultaneously.

Keywords:
BRCA1DNA helicaseFANCJFBH1Förster resonance energy transfer (FRET)PhosphorylationSingle-moleculeTotal internal reflection fluorescence microscopyUbiquitylation

More Related Videos

Parallel High Throughput Single Molecule Kinetic Assay for Site-Specific DNA Cleavage
06:51

Parallel High Throughput Single Molecule Kinetic Assay for Site-Specific DNA Cleavage

Published on: May 6, 2020

4.4K
Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
08:28

Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers

Published on: September 19, 2017

8.7K

Related Experiment Videos

Last Updated: Mar 20, 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

2.6K
Parallel High Throughput Single Molecule Kinetic Assay for Site-Specific DNA Cleavage
06:51

Parallel High Throughput Single Molecule Kinetic Assay for Site-Specific DNA Cleavage

Published on: May 6, 2020

4.4K
Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
08:28

Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers

Published on: September 19, 2017

8.7K

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Genetics

Background:

  • DNA helicases are crucial for DNA metabolism, utilizing ATP for translocation and unwinding.
  • Post-translational modifications regulate helicase activity and function, but studying them is challenging.
  • Traditional methods struggle to provide sufficient quantities of modified helicases for analysis.

Purpose of the Study:

  • To overcome limitations in studying human DNA helicase modifications.
  • To develop a method for analyzing helicase activity with native post-translational modifications.
  • To enable direct evaluation of modification effects on helicase function.

Main Methods:

  • Developed "single-molecule sorting" using total internal reflection fluorescence microscopy.
  • Produced and biotinylated DNA helicases in human cells for surface tethering.
  • Utilized site-specifically labeled synthetic DNA substrates (Cy3/Cy5) for analysis.

Main Results:

  • Successfully quantified and distinguished activities of modified and unmodified helicases in a single experiment.
  • Enabled kinetic and thermodynamic characterization of helicase-substrate interactions.
  • Demonstrated a direct route to assess the impact of post-translational modifications.

Conclusions:

  • Single-molecule sorting is a robust approach for studying native, modified DNA helicases.
  • This technique facilitates mechanistic understanding of helicase regulation by modifications.
  • Provides a powerful tool for advancing DNA repair and replication research.