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

Mismatch Repair01:20

Mismatch Repair

4.8K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
4.8K
DNA Damage can Stall the Cell Cycle02:37

DNA Damage can Stall the Cell Cycle

9.2K
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.2K
The Spindle Assembly Checkpoint02:19

The Spindle Assembly Checkpoint

3.2K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.2K
Nucleosome Remodeling02:54

Nucleosome Remodeling

9.1K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.1K
Base-pairing and DNA Repair02:27

Base-pairing and DNA Repair

64.7K
64.7K
Heterochromatin02:38

Heterochromatin

12.7K
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...
12.7K

You might also read

Related Articles

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

Sort by
Same author

Programming T cells for intercellular genome editing.

bioRxiv : the preprint server for biology·2026
Same author

Harmonizing standards and resources for the medical genome.

Nature·2026
Same author

Publisher Correction: Lung and liver editing by lipid nanoparticle delivery of a stable CRISPR-Cas9 ribonucleoprotein.

Nature biotechnology·2026
Same author

Targeting Cancer-Specific Mutations with RNA-Triggered Chromatin Shredding.

Nature·2026
Same author

Selective Elimination of TP53 Mutant Cells by Transcript-Activated Chromatin Shredding.

bioRxiv : the preprint server for biology·2026
Same author

The phage nucleus synergizes with an anti-defense protein to resist bacterial immunity.

Cell reports·2026
Same journal

A human-specific genetic modifier reconfigures large-scale cortical network dynamics underlying behavioral performance.

bioRxiv : the preprint server for biology·2026
Same journal

<i>Staphylococcus aureus</i> uses a eukaryotic-like uridyltransferase to make UDP-GlcNAc for cell wall synthesis.

bioRxiv : the preprint server for biology·2026
Same journal

Dynamic redistribution of eIF4F controls cap-dependent translation initiation.

bioRxiv : the preprint server for biology·2026
Same journal

When does additional information improve accuracy of RNA secondary structure prediction?

bioRxiv : the preprint server for biology·2026
Same journal

Normative brain-state trajectories reveal deviation from healthy aging in Alzheimer's disease.

bioRxiv : the preprint server for biology·2026
Same journal

Noradrenergic infraslow rhythm during sleep is the critical link between heart-rate dynamics and memory consolidation.

bioRxiv : the preprint server for biology·2026
See all related articles

Related Experiment Video

Updated: Jul 1, 2025

DamID-seq: Genome-wide Mapping of Protein-DNA Interactions by High Throughput Sequencing of Adenine-methylated DNA Fragments
09:14

DamID-seq: Genome-wide Mapping of Protein-DNA Interactions by High Throughput Sequencing of Adenine-methylated DNA Fragments

Published on: January 27, 2016

19.5K

Hachiman is a genome integrity sensor.

Owen T Tuck1,2, Benjamin A Adler2,3, Emily G Armbruster4

  • 1Department of Chemistry, University of California, Berkeley, Berkeley, CA USA.

Biorxiv : the Preprint Server for Biology
|March 11, 2024
PubMed
Summary
This summary is machine-generated.

The Hachiman antiphage system uses a HamAB nuclease-helicase complex to defend against DNA damage. Upon detecting aberrant DNA, it degrades all cellular DNA, creating phantom cells.

More Related Videos

Author Spotlight: Decoding DNA Repair by Extrachromosomal NHEJ Assay and HR Assays
09:29

Author Spotlight: Decoding DNA Repair by Extrachromosomal NHEJ Assay and HR Assays

Published on: February 2, 2024

2.1K
Genome-wide Mapping of Protein-DNA Interactions with ChEC-seq in Saccharomyces cerevisiae
10:43

Genome-wide Mapping of Protein-DNA Interactions with ChEC-seq in Saccharomyces cerevisiae

Published on: June 3, 2017

11.2K

Related Experiment Videos

Last Updated: Jul 1, 2025

DamID-seq: Genome-wide Mapping of Protein-DNA Interactions by High Throughput Sequencing of Adenine-methylated DNA Fragments
09:14

DamID-seq: Genome-wide Mapping of Protein-DNA Interactions by High Throughput Sequencing of Adenine-methylated DNA Fragments

Published on: January 27, 2016

19.5K
Author Spotlight: Decoding DNA Repair by Extrachromosomal NHEJ Assay and HR Assays
09:29

Author Spotlight: Decoding DNA Repair by Extrachromosomal NHEJ Assay and HR Assays

Published on: February 2, 2024

2.1K
Genome-wide Mapping of Protein-DNA Interactions with ChEC-seq in Saccharomyces cerevisiae
10:43

Genome-wide Mapping of Protein-DNA Interactions with ChEC-seq in Saccharomyces cerevisiae

Published on: June 3, 2017

11.2K

Area of Science:

  • Bacteriology
  • Molecular Biology
  • Genetics

Background:

  • The Hachiman system is a broad-spectrum antiphage defense mechanism in bacteria with an uncharacterized function.
  • Understanding bacterial immune systems is crucial for developing novel antimicrobial strategies.

Approach:

  • Investigated the molecular components and mechanism of the Hachiman system.
  • Utilized biochemical assays to characterize the nuclease and helicase activities of the HamAB complex.
  • Examined Hachiman activation in response to DNA damage using various experimental conditions.

Key Points:

  • Hachiman functions as a heterodimeric nuclease-helicase complex, HamAB, composed of the effector nuclease HamA and the sensor helicase HamB.
  • HamB regulates HamA activity, constraining it during surveillance of intact double-stranded DNA (dsDNA).
  • Upon detection of DNA damage, HamB's helicase activity releases HamA, activating potent nuclease activity that degrades all cellular DNA, forming 'phantom' cells.

Conclusions:

  • The Hachiman system acts as a DNA damage response system, not solely an antiphage defense.
  • Phylogenetic analysis suggests the Hachiman helicase has homologs in eukaryotes, indicating potential ancient origins and diverse functional repurposing across life domains.
  • This discovery opens new avenues for understanding bacterial immunity and the evolution of DNA-processing enzymes.