4EE2

Crystal Structure of Anthrax Protective Antigen K446M Mutant to 1.91-A Resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.91 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.229 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Anthrax toxin protective antigen integrates poly-gamma-D-glutamate and pH signals to sense the optimal environment for channel formation.

Kintzer, A.F.Tang, I.I.Schawel, A.K.Brown, M.J.Krantz, B.A.

(2012) Proc.Natl.Acad.Sci.USA 109: 18378-18383

  • DOI: 10.1073/pnas.1208280109

  • PubMed Abstract: 
  • Many toxins assemble into oligomers on the surface of cells. Local chemical cues signal and trigger critical rearrangements of the oligomer, inducing the formation of a membrane-fused or channel state. Bacillus anthracis secretes two virulence factor ...

    Many toxins assemble into oligomers on the surface of cells. Local chemical cues signal and trigger critical rearrangements of the oligomer, inducing the formation of a membrane-fused or channel state. Bacillus anthracis secretes two virulence factors: a tripartite toxin and a poly-γ-d-glutamic acid capsule (γ-DPGA). The toxin's channel-forming component, protective antigen (PA), oligomerizes to create a prechannel that forms toxic complexes upon binding the two other enzyme components, lethal factor (LF) and edema factor (EF). Following endocytosis into host cells, acidic pH signals the prechannel to form the channel state, which translocates LF and EF into the host cytosol. We report γ-DPGA binds to PA, LF, and EF, exhibiting nanomolar avidity for the PA prechannel oligomer. We show PA channel formation requires the pH-dependent disruption of the intra-PA domain-2-domain-4 (D2-D4) interface. γ-DPGA stabilizes the D2-D4 interface, preventing channel formation both in model membranes and cultured mammalian cells. A 1.9-Å resolution X-ray crystal structure of a D2-D4-interface mutant and corresponding functional studies reveal how stability at the intra-PA interface governs channel formation. We also pinpoint the kinetic pH trigger for channel formation to a residue within PA's membrane-insertion loop at the inter-PA D2-D4 interface. Thus, γ-DPGA may function as a chemical cue, signaling that the local environment is appropriate for toxin assembly but inappropriate for channel formation.


    Organizational Affiliation

    Department of Chemistry, University of California, Berkeley, CA 94720, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protective antigen
A
736Bacillus anthracisMutation(s): 1 
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: 1.91 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.229 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 71.216α = 90.00
b = 93.512β = 90.00
c = 116.918γ = 90.00
Software Package:
Software NamePurpose
ADSCdata collection
HKL-2000data reduction
PHENIXrefinement
SCALEPACKdata scaling
DENZOdata reduction
PDB_EXTRACTdata extraction
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-10-24
    Type: Initial release
  • Version 1.1: 2013-09-04
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Refinement description