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

CRISPR01:59

CRISPR

57.4K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
57.4K
CRISPR/Cas9 Genome Editing01:28

CRISPR/Cas9 Genome Editing

1.6K
The CRISPR-Cas system serves as a bacterial defense mechanism against invading genetic elements such as viruses and plasmids, forming the foundation for its adaptation as a powerful genome-editing tool. Originally discovered in prokaryotes, this system has been repurposed to revolutionize genetic engineering across a wide range of organisms, including plants, animals, and humans. The core component, Cas9, is an endonuclease derived from Streptococcus pyogenes, capable of introducing...
1.6K
Homologous Recombination02:31

Homologous Recombination

62.4K
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...
62.4K
DNA Helicases00:55

DNA Helicases

23.8K
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...
23.8K
CRISPR and crRNAs02:53

CRISPR and crRNAs

18.7K
Bacteria and archaea are susceptible to viral infections just like eukaryotes; therefore, they have developed a unique adaptive immune system to protect themselves. Clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins (CRISPR-Cas) are present in more than 45% of known bacteria and 90% of known archaea.
The CRISPR-Cas system stores a copy of foreign DNA in the host genome and uses it to identify the foreign DNA upon reinfection. CRISPR-Cas has three different...
18.7K
DNA Topoisomerases02:02

DNA Topoisomerases

34.6K
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. ...
34.6K

You might also read

Related Articles

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

Sort by
Same author

Off-target detection of CRISPR-Cas9 nuclease <i>in vitro</i> with CROFT-Seq.

Synthetic biology (Oxford, England)·2026
Same author

TIR domains produce histidine-ADPR as an immune signal in bacteria.

Nature·2025
Same author

Activation of Thoeris antiviral system via SIR2 effector filament assembly.

Nature·2024
Same author

Innate programmable DNA binding by CRISPR-Cas12m effectors enable efficient base editing.

Nucleic acids research·2024
Same author

Ribosomal stalk-captured CARF-RelE ribonuclease inhibits translation following CRISPR signaling.

Science (New York, N.Y.)·2023
Same author

TnpB structure reveals minimal functional core of Cas12 nuclease family.

Nature·2023

Related Experiment Video

Updated: Jan 8, 2026

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms
09:51

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

35.4K

A DNA mimic jams the Cas9 scissors.

Tomas Sinkunas1, Giedre Tamulaitiene1

  • 1Institute of Biotechnology, Life Sciences Center, Vilnius University, Lithuania.

The FEBS Journal
|December 16, 2025
PubMed
Summary

New anti-CRISPR (Acr) proteins inhibit CRISPR-Cas enzymes. AcrIIA13b was discovered to act as a DNA mimic, blocking Cas9 binding to DNA targets.

Area of Science:

  • Molecular Biology
  • Biochemistry
  • Genetics

Background:

  • CRISPR-Cas systems are microbial adaptive immune mechanisms targeting nucleic acids.
  • Anti-CRISPR (Acr) proteins are diverse inhibitors of CRISPR-Cas activity.
  • Acr proteins exhibit varied structures and inhibition mechanisms.

Purpose of the Study:

  • To characterize the novel AcrIIA13b protein.
  • To elucidate the mechanism by which AcrIIA13b inhibits the Cas9 enzyme.

Main Methods:

  • Structural analysis of AcrIIA13b.
  • Biochemical assays to assess Cas9 inhibition.
  • Mutational analysis to identify key residues for DNA mimicry.

Main Results:

Keywords:
AcrAnti‐CRISPRCRISPR‐CasDNA mimicry

More Related Videos

High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots
12:59

High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots

Published on: April 30, 2016

18.6K
Genome Editing in Mammalian Cell Lines using CRISPR-Cas
07:56

Genome Editing in Mammalian Cell Lines using CRISPR-Cas

Published on: April 11, 2019

23.0K

Related Experiment Videos

Last Updated: Jan 8, 2026

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms
09:51

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

35.4K
High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots
12:59

High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots

Published on: April 30, 2016

18.6K
Genome Editing in Mammalian Cell Lines using CRISPR-Cas
07:56

Genome Editing in Mammalian Cell Lines using CRISPR-Cas

Published on: April 11, 2019

23.0K
  • AcrIIA13b was identified as a novel inhibitor of the Cas9 protein.
  • Structural and biochemical data revealed AcrIIA13b functions as a DNA mimic.
  • AcrIIA13b prevents Cas9 from binding to its DNA target by mimicking DNA.

    • Conclusions:

    • AcrIIA13b represents a new class of anti-CRISPR proteins.
    • The DNA mimicry mechanism of AcrIIA13b provides insights into Cas9 regulation.
    • Understanding AcrIIA13b's function could inform the development of novel gene-editing tools.