3J9C

CryoEM single particle reconstruction of anthrax toxin protective antigen pore at 2.9 Angstrom resolution


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.9 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Atomic structure of anthrax protective antigen pore elucidates toxin translocation.

Jiang, J.Pentelute, B.L.Collier, R.J.Zhou, Z.H.

(2015) Nature 521: 545-549

  • DOI: 10.1038/nature14247

  • PubMed Abstract: 
  • Anthrax toxin, comprising protective antigen, lethal factor, and oedema factor, is the major virulence factor of Bacillus anthracis, an agent that causes high mortality in humans and animals. Protective antigen forms oligomeric prepores that undergo ...

    Anthrax toxin, comprising protective antigen, lethal factor, and oedema factor, is the major virulence factor of Bacillus anthracis, an agent that causes high mortality in humans and animals. Protective antigen forms oligomeric prepores that undergo conversion to membrane-spanning pores by endosomal acidification, and these pores translocate the enzymes lethal factor and oedema factor into the cytosol of target cells. Protective antigen is not only a vaccine component and therapeutic target for anthrax infections but also an excellent model system for understanding the mechanism of protein translocation. On the basis of biochemical and electrophysiological results, researchers have proposed that a phi (Φ)-clamp composed of phenylalanine (Phe)427 residues of protective antigen catalyses protein translocation via a charge-state-dependent Brownian ratchet. Although atomic structures of protective antigen prepores are available, how protective antigen senses low pH, converts to active pore, and translocates lethal factor and oedema factor are not well defined without an atomic model of its pore. Here, by cryo-electron microscopy with direct electron counting, we determine the protective antigen pore structure at 2.9-Å resolution. The structure reveals the long-sought-after catalytic Φ-clamp and the membrane-spanning translocation channel, and supports the Brownian ratchet model for protein translocation. Comparisons of four structures reveal conformational changes in prepore to pore conversion that support a multi-step mechanism by which low pH is sensed and the membrane-spanning channel is formed.


    Organizational Affiliation

    1] Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California 90095, USA [2] California NanoSystems Institute, University of California, Los Angeles, California 90095, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protective antigen PA-63
A
562Bacillus anthracisMutation(s): 0 
Gene Names: pagA (pag)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Adventitious Membrane Proteins: Beta-sheet Pore-forming Toxins/Attack Complexes
Protein: 
Anthrax Protective Antigen (PA) and Lethal Factor (LF) Prechannel Complex
Find proteins for P13423 (Bacillus anthracis)
Go to UniProtKB:  P13423
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.9 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-03-11
    Type: Initial release
  • Version 1.1: 2015-06-03
    Type: Database references
  • Version 1.2: 2015-06-10
    Type: Database references
  • Version 1.3: 2018-07-18
    Type: Data collection