Structural basis for the procoagulant activity of staphylocoagulase.
2026-08-20, Biological chemistry (10.1515/hsz-2025-0253) (online)Pablo Fuentes-Prior, Peter Panizzi, Ashoka A Maddur, David Gailani, and Ingrid M Verhamme (?)
Staphylocoagulase (SC), a crucial virulence protein secreted by several strains of the major pathogen , functions as a potent inducer of blood clotting. SC binds its zymogen target, prothrombin (ProT) with subnanomolar affinity, allosterically inducing a thrombin-like active site in the bound zymogen. The resulting SC·(Pro)T* active complexes effectively convert fibrinogen (Fbg) into clot-forming fibrin (Fbn). We previously reported crystal structures of the N-terminal SC domains, responsible for ProT binding and activation, and characterized the mechanism of cofactor-induced zymogen activation in detail. However, the lack of three-dimensional (3D) structures for the C-terminal SC region has hampered a complete understanding of its role in Fbg recognition and cleavage. Here, we present and discuss 3D models of the Fbg-binding SC region. Our results suggest that the major C-terminal domain of SC folds into a single-layer β-sheet structurally similar to the membrane occupation and recognition nexus (MORN) family of tandem repeats. We further propose a folding pathway for this C-terminal SC region that is contingent upon the presence of its substrate, Fbg. These structural and mechanistic insights are critical for understanding SC-mediated fibrin generation, which is highly relevant to heart valve vegetations and biofilm formation during infection.
This article has not yet been included in any curations.



Comments
There are no comments on this article yet.
You need to login or register to comment.