1ACC

ANTHRAX PROTECTIVE ANTIGEN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the anthrax toxin protective antigen.

Petosa, C.Collier, R.J.Klimpel, K.R.Leppla, S.H.Liddington, R.C.

(1997) Nature 385: 833-838

  • DOI: 10.1038/385833a0

  • PubMed Abstract: 
  • Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. After proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that ...

    Protective antigen (PA) is the central component of the three-part protein toxin secreted by Bacillus anthracis, the organism responsible for anthrax. After proteolytic activation on the host cell surface, PA forms a membrane-inserting heptamer that translocates the toxic enzymes, oedema factor and lethal factor, into the cytosol. PA, which has a relative molecular mass of 83,000 (M(r) 83K), can also translocate heterologous proteins, and is being evaluated for use as a general protein delivery system. Here we report the crystal structure of monomeric PA at 2.1 A resolution and the water-soluble heptamer at 4.5 A resolution. The monomer is organized mainly into antiparallel beta-sheets and has four domains: an amino-terminal domain (domain 1) containing two calcium ions and the cleavage site for activating proteases; a heptamerization domain (domain 2) containing a large flexible loop implicated in membrane insertion; a small domain of unknown function (domain 3); and a carboxy-terminal receptor-binding domain (domain 4). Removal of a 20K amino-terminal fragment from domain 1 allows the assembly of the heptamer, a ring-shaped structure with a negatively charged lumen, and exposes a large hydrophobic surface for binding the toxic enzymes. We propose a model of pH-dependent membrane insertion involving the formation of a porin-like, membrane-spanning beta-barrel.


    Organizational Affiliation

    Biochemistry Department, University of Leicester, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANTHRAX PROTECTIVE ANTIGEN
A
735Bacillus anthracisMutation(s): 0 
Gene Names: pagA (pag)
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: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.223 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 99.300α = 90.00
b = 93.700β = 90.00
c = 82.000γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
X-PLORphasing
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-02-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance