6ZXJ

Fully-loaded anthrax lethal toxin in its heptameric pre-pore state, in which the third lethal factor is masked out (PA7LF3-masked)


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Models: experimental
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This is version 1.1 of the entry. See complete history


Literature

Cryo-EM structure of the fully-loaded asymmetric anthrax lethal toxin in its heptameric pre-pore state.

Antoni, C.Quentin, D.Lang, A.E.Aktories, K.Gatsogiannis, C.Raunser, S.

(2020) PLoS Pathog 16: e1008530-e1008530

  • DOI: https://doi.org/10.1371/journal.ppat.1008530
  • Primary Citation of Related Structures:  
    6ZXJ, 6ZXK, 6ZXL

  • PubMed Abstract: 

    Anthrax toxin is the major virulence factor secreted by Bacillus anthracis, causing high mortality in humans and other mammals. It consists of a membrane translocase, known as protective antigen (PA), that catalyzes the unfolding of its cytotoxic substrates lethal factor (LF) and edema factor (EF), followed by translocation into the host cell. Substrate recruitment to the heptameric PA pre-pore and subsequent translocation, however, are not well understood. Here, we report three high-resolution cryo-EM structures of the fully-loaded anthrax lethal toxin in its heptameric pre-pore state, which differ in the position and conformation of LFs. The structures reveal that three LFs interact with the heptameric PA and upon binding change their conformation to form a continuous chain of head-to-tail interactions. As a result of the underlying symmetry mismatch, one LF binding site in PA remains unoccupied. Whereas one LF directly interacts with a part of PA called α-clamp, the others do not interact with this region, indicating an intermediate state between toxin assembly and translocation. Interestingly, the interaction of the N-terminal domain with the α-clamp correlates with a higher flexibility in the C-terminal domain of the protein. Based on our data, we propose a model for toxin assembly, in which the relative position of the N-terminal α-helices in the three LFs determines which factor is translocated first.


  • Organizational Affiliation

    Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Protective antigen
A, B, C, D, E
A, B, C, D, E, F, G
759Bacillus 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
Lethal factor
H, I
809Bacillus anthracisMutation(s): 0 
Gene Names: lefpXO1-107BXA0172GBAA_pXO1_0172
EC: 3.4.24.83
UniProt
Find proteins for P15917 (Bacillus anthracis)
Explore P15917 
Go to UniProtKB:  P15917
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP15917
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONSPHIRE
MODEL REFINEMENTPHENIX1.18.2
MODEL REFINEMENTCoot0.8.9.1

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
European Research Council (ERC)Germany615984

Revision History  (Full details and data files)

  • Version 1.0: 2020-09-02
    Type: Initial release
  • Version 1.1: 2024-05-01
    Changes: Data collection, Database references, Refinement description