1ACC

ANTHRAX PROTECTIVE ANTIGEN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.223 
  • R-Value Observed: 0.223 

wwPDB Validation   3D Report Full Report


This is version 1.3 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: https://doi.org/10.1038/385833a0
  • Primary Citation of Related Structures:  
    1ACC

  • 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 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ANTHRAX PROTECTIVE ANTIGEN735Bacillus anthracisMutation(s): 0 
UniProt
Find proteins for P13423 (Bacillus anthracis)
Explore P13423 
Go to UniProtKB:  P13423
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP13423
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.296 
  • R-Value Work: 0.223 
  • R-Value Observed: 0.223 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 99.3α = 90
b = 93.7β = 90
c = 82γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-02-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Derived calculations, Other