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

Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

863
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
863
Structure of Porins01:21

Structure of Porins

4.1K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a  motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
4.1K
Receptor-mediated Endocytosis01:20

Receptor-mediated Endocytosis

11.1K
Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
11.1K
Protein Complex Assembly02:41

Protein Complex Assembly

17.0K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types.  Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
17.0K
The Proteasome Structure01:17

The Proteasome Structure

2.0K
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
2.0K
Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

5.1K
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
5.1K

You might also read

Related Articles

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

Sort by
Same author

A conserved VPS34-PIKfyve-TRPML1-myosin II axis regulates the speed of amoeboid cell migration.

EMBO reports·2026
Same author

Biolayer Interferometry for Investigating Membrane Protein-Inhibitor Binding: TACAN Mutant and GsMTx4 As a Model System.

Journal of visualized experiments : JoVE·2026
Same author

Bringing the ends together: cryo-EM structures of mycobacterial Ku in complex with DNA define its role in NHEJ synapsis.

Nucleic acids research·2026
Same author

The Effects of Occupational and Leisure Time Physical Activity on Health-Related Quality of Life: A Repeated-Measures Longitudinal Study.

Sports medicine (Auckland, N.Z.)·2026
Same author

Optimization of a synoviocyte-targeted biologic for inflammatory arthritis in combination or bispecific administration with TNF inhibitors.

JCI insight·2025
Same author

PTPN22-CD45 dual phosphatase retrograde feedback enhances TCR signaling and autoimmunity.

Science advances·2025

Related Experiment Video

Updated: Mar 14, 2026

Analyzing Dynamic Protein Complexes Assembled On and Released From Biolayer Interferometry Biosensor Using Mass Spectrometry and Electron Microscopy
09:30

Analyzing Dynamic Protein Complexes Assembled On and Released From Biolayer Interferometry Biosensor Using Mass Spectrometry and Electron Microscopy

Published on: August 6, 2018

10.0K

Structure of anthrax lethal toxin prepore complex suggests a pathway for efficient cell entry.

Lucien Fabre1, Eugenio Santelli2, Driss Mountassif1

  • 1Department of Anatomy and Cell Biology, McGill University, Montréal, Québec H3A 0C7, Canada Groupe de Recherche Axé sur la Structure des Protéines (GRASP), Groupe d'Étude des Protéines Membranaires (GÉPROM), McGill University, Montréal, Québec H3A 0C7, Canada.

The Journal of General Physiology
|September 28, 2016
PubMed
Summary

Anthrax toxin

More Related Videos

Deciphering the Molecular Mechanism and Function of Pore-Forming Toxins Using Leishmania major
08:17

Deciphering the Molecular Mechanism and Function of Pore-Forming Toxins Using Leishmania major

Published on: October 28, 2022

2.0K
Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance
10:41

Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance

Published on: January 3, 2012

13.8K

Related Experiment Videos

Last Updated: Mar 14, 2026

Analyzing Dynamic Protein Complexes Assembled On and Released From Biolayer Interferometry Biosensor Using Mass Spectrometry and Electron Microscopy
09:30

Analyzing Dynamic Protein Complexes Assembled On and Released From Biolayer Interferometry Biosensor Using Mass Spectrometry and Electron Microscopy

Published on: August 6, 2018

10.0K
Deciphering the Molecular Mechanism and Function of Pore-Forming Toxins Using Leishmania major
08:17

Deciphering the Molecular Mechanism and Function of Pore-Forming Toxins Using Leishmania major

Published on: October 28, 2022

2.0K
Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance
10:41

Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance

Published on: January 3, 2012

13.8K

Area of Science:

  • Molecular biology
  • Structural biology
  • Biochemistry

Background:

  • Anthrax toxin is a tripartite complex essential for virulence.
  • Protective antigen (PA) forms a pore for lethal factor (LF) and edema factor (EF) delivery.
  • Understanding the translocation mechanism is crucial for developing therapeutics.

Purpose of the Study:

  • To elucidate the molecular basis of efficient lethal factor translocation through the protective antigen pore.
  • To determine the structure of the fully loaded anthrax toxin prepore complex.

Main Methods:

  • Cryo-electron microscopy (cryo-EM) to generate a 3D map.
  • Structural analysis of the (PA63)7-(LF)3 prepore complex.

Main Results:

  • A 3D map of the fully loaded (PA63)7-(LF)3 prepore complex was calculated.
  • Three lethal factor molecules bind via their N-terminal domains to the protective antigen heptamer.
  • Contacts between N- and C-terminal domains of adjacent lethal factors were observed.

Conclusions:

  • The observed molecular arrangement of lethal factor within the protective antigen pore is proposed to maintain translocation efficiency.
  • This structural insight provides a basis for understanding anthrax toxin pore function.