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

The Replisome03:01

The Replisome

33.5K
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with...
33.5K
Cytoskeletal Proteins in Bacteria01:29

Cytoskeletal Proteins in Bacteria

3.4K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.4K
Intracellular Movement of Viruses and Bacteria01:10

Intracellular Movement of Viruses and Bacteria

2.8K
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a...
2.8K
Clathrin Coated Vesicles01:12

Clathrin Coated Vesicles

7.0K
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
7.0K
Prokaryotic Cells01:51

Prokaryotic Cells

122.6K
Prokaryotes are small unicellular organisms that include the domains—Archaea and Bacteria. Bacteria include many common organisms, such as Salmonella and E. coli, while the Archaea include extremophiles that live in harsh environments, such as volcanic springs.
Like eukaryotic cells, all prokaryotic cells are surrounded by a plasma membrane, have genetic material in the form of single, circular DNA, a cytoplasm that fills the interior of the cell, and ribosomes that synthesize proteins....
122.6K
Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes02:16

Comparing Mitochondrial, Chloroplast, and Prokaryotic Genomes

12.5K
The present-day mitochondrial and chloroplast genomes have retained some of the characteristics of their ancestral prokaryotes and also have acquired new attributes during their evolution within eukaryotic cells. Like prokaryotic genomes, mitochondrial and chloroplast genomes neither bind with histone-like proteins nor show complex packaging into chromosome-like structures, as observed in eukaryotes. Unlike mitotic cell divisions observed in eukaryotic cells, mitochondria and chloroplasts...
12.5K

You might also read

Related Articles

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

Sort by
Same author

Cooperativity and communication between the active sites of the dimeric SARS-CoV-2 main protease.

Science advances·2026
Same author

PCNA is a nucleotide exchange factor for the clamp loader ATPase complex.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

The structure of a thermostable phage's portal vertex and neck complex illuminates the headful maturation mechanism.

bioRxiv : the preprint server for biology·2025
Same author

PCNA is a Nucleotide Exchange Factor for the Clamp Loader ATPase Complex.

bioRxiv : the preprint server for biology·2025
Same author

Regulation of the ordinal DNA translocation cycle in bacteriophage Φ29 through trans-subunit interactions.

Proceedings of the National Academy of Sciences of the United States of America·2025
Same author

An antisense RNA regulates production of DnaA and affects sporulation in Bacillus subtilis.

PLoS genetics·2025

Related Experiment Video

Updated: Jul 8, 2025

In vivo and in vitro Studies of Adaptor-clathrin Interaction
17:14

In vivo and in vitro Studies of Adaptor-clathrin Interaction

Published on: January 26, 2011

14.6K

Differences in clamp loader mechanism between bacteria and eukaryotes.

Jacob T Landeck1, Joshua Pajak1, Emily K Norman1

  • 1Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester MA.

Biorxiv : the Preprint Server for Biology
|December 11, 2023
PubMed
Summary

The E. coli clamp loader opens DNA sliding clamps via a crab-claw motion, revealing multi-step opening and distinct mechanisms from eukaryotic RFC. This clarifies DNA replication machinery across life.

Keywords:
AAA+ ATPaseDNA replicationbacteriaclamp loadercryo-EM

More Related Videos

Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series
07:59

Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series

Published on: May 10, 2020

7.7K
Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
10:41

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

13.9K

Related Experiment Videos

Last Updated: Jul 8, 2025

In vivo and in vitro Studies of Adaptor-clathrin Interaction
17:14

In vivo and in vitro Studies of Adaptor-clathrin Interaction

Published on: January 26, 2011

14.6K
Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series
07:59

Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series

Published on: May 10, 2020

7.7K
Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
10:41

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation

Published on: January 4, 2017

13.9K

Area of Science:

  • Molecular Biology
  • Structural Biology
  • Biochemistry

Background:

  • Clamp loaders are essential pentameric ATPases that load circular sliding clamps onto DNA, crucial for replication and genome stability.
  • The mechanism of clamp loading is conserved across life, but specific differences exist between organisms.
  • Previous studies on eukaryotic Replication Factor C (RFC) suggested a crab-claw mechanism involving large conformational changes.

Approach:

  • High-resolution cryo-electron microscopy (cryo-EM) was used to investigate the clamp loading mechanism of the E. coli clamp loader.
  • Structures were determined at various stages of clamp opening and in the presence of primer-template junctions.

Key Points:

  • The E. coli clamp loader utilizes a crab-claw motion at a single pivot point for clamp opening, differing from the distributed motions in eukaryotic RFC.
  • Clamp opening proceeds in multiple steps, involving a spiral conformation in a partly open state and a planar geometry in the fully open state.
  • Structures reveal how the clamp loader closes the clamp around primer-template junctions and initiates release after loading.

Conclusions:

  • Mechanistic distinctions exist in the conserved clamp loader machinery between E. coli and eukaryotes.
  • The multi-step, single-pivot mechanism in E. coli provides new insights into the universal process of DNA clamp loading.
  • This research deepens our understanding of DNA replication and genome integrity mechanisms across all domains of life.