6WTS image
Deposition Date 2020-05-03
Release Date 2020-07-08
Last Version Date 2024-10-09
Entry Detail
PDB ID:
6WTS
Title:
CryoEM structure of the C. sordellii lethal toxin TcsL in complex with SEMA6A
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.30 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:SEMA6A
Gene (Uniprot):SEMA6A
Chain IDs:A, B
Chain Length:564
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:TcsL
Chain IDs:C
Chain Length:552
Number of Molecules:1
Biological Source:Paeniclostridium sordellii
Ligand Molecules
Primary Citation
Recognition of Semaphorin Proteins by P. sordellii Lethal Toxin Reveals Principles of Receptor Specificity in Clostridial Toxins.
Cell 182 345 ? (2020)
PMID: 32589945 DOI: 10.1016/j.cell.2020.06.005

Abstact

Pathogenic clostridial species secrete potent toxins that induce severe host tissue damage. Paeniclostridium sordellii lethal toxin (TcsL) causes an almost invariably lethal toxic shock syndrome associated with gynecological infections. TcsL is 87% similar to C. difficile TcdB, which enters host cells via Frizzled receptors in colon epithelium. However, P. sordellii infections target vascular endothelium, suggesting that TcsL exploits another receptor. Here, using CRISPR/Cas9 screening, we establish semaphorins SEMA6A and SEMA6B as TcsL receptors. We demonstrate that recombinant SEMA6A can protect mice from TcsL-induced edema. A 3.3 Å cryo-EM structure shows that TcsL binds SEMA6A with the same region that in TcdB binds structurally unrelated Frizzled. Remarkably, 15 mutations in this evolutionarily divergent surface are sufficient to switch binding specificity of TcsL to that of TcdB. Our findings establish semaphorins as physiologically relevant receptors for TcsL and reveal the molecular basis for the difference in tissue targeting and disease pathogenesis between highly related toxins.

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Primary Citation of related structures