PMID: 21475196 , Related PDB ids: 2XNX, 2XNY

Authors:

Macheboeuf P, Buffalo C, Fu CY, Zinkernagel AS, Cole JN, Johnson JE, Nizet V, Ghosh P

Title:

Streptococcal M1 protein constructs a pathological host fibrinogen network.

Journal:

Nature. 2011 Apr 7;472(7341):64-8.

Abstract:

M1 protein, a major virulence factor of the leading invasive strain of group A Streptococcus, is sufficient to induce toxic-shock-like vascular leakage and tissue injury. These events are triggered by the formation of a complex between M1 and fibrinogen that, unlike M1 or fibrinogen alone, leads to neutrophil activation. Here we provide a structural explanation for the pathological properties of the complex formed between streptococcal M1 and human fibrinogen. A conformationally dynamic coiled-coil dimer of M1 was found to organize four fibrinogen molecules into a specific cross-like pattern. This pattern supported the construction of a supramolecular network that was required for neutrophil activation but was distinct from a fibrin clot. Disruption of this network into other supramolecular assemblies was not tolerated. These results have bearing on the pathophysiology of streptococcal toxic shock.