1T6B

Crystal structure of B. anthracis Protective Antigen complexed with human Anthrax toxin receptor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.210 

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This is version 1.3 of the entry. See complete history


Literature

Crystal structure of a complex between anthrax toxin and its host cell receptor

Santelli, E.Bankston, L.A.Leppla, S.H.Liddington, R.C.

(2004) Nature 430: 905-908

  • DOI: https://doi.org/10.1038/nature02763
  • Primary Citation of Related Structures:  
    1T6B

  • PubMed Abstract: 

    Anthrax toxin consists of the proteins protective antigen (PA), lethal factor (LF) and oedema factor (EF). The first step of toxin entry into host cells is the recognition by PA of a receptor on the surface of the target cell. Subsequent cleavage of receptor-bound PA enables EF and LF to bind and form a heptameric PA63 pre-pore, which triggers endocytosis. Upon acidification of the endosome, PA63 forms a pore that inserts into the membrane and translocates EF and LF into the cytosol. Two closely related host cell receptors, TEM8 and CMG2, have been identified. Both bind to PA with high affinity and are capable of mediating toxicity. Here, we report the crystal structure of the PA-CMG2 complex at 2.5 A resolution. The structure reveals an extensive receptor-pathogen interaction surface mimicking the non-pathogenic recognition of the extracellular matrix by integrins. The binding surface is closely conserved in the two receptors and across species, but is quite different in the integrin domains, explaining the specificity of the interaction. CMG2 engages two domains of PA, and modelling of the receptor-bound PA63 heptamer suggests that the receptor acts as a pH-sensitive brace to ensure accurate and timely membrane insertion. The structure provides new leads for the discovery of anthrax anti-toxins, and should aid the design of cancer therapeutics.


  • Organizational Affiliation

    Program on Cell Adhesion, The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Protective AntigenA [auth X]735Bacillus 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
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Anthrax toxin receptor 2B [auth Y]189Homo sapiensMutation(s): 0 
Gene Names: ANTXR2CMG2
UniProt & NIH Common Fund Data Resources
Find proteins for P58335 (Homo sapiens)
Explore P58335 
Go to UniProtKB:  P58335
PHAROS:  P58335
GTEx:  ENSG00000163297 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP58335
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.210 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.16α = 90
b = 94.118β = 90
c = 135.597γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
MOLREPphasing
REFMACrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-07-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2024-02-14
    Changes: Data collection, Database references, Derived calculations