Cutting edge: members of the Staphylococcus aureus extracellular fibrinogen-binding protein family inhibit the interaction of C3d with complement receptor 2.

Cutting Edge: Members of the Staphylococcus aureus Extracellular Fibrinogen-Binding Protein Family Inhibit the Interaction of C3d with Complement

Identification and characterization of the C3 binding domain of the Staphylococcus aureus extracellular fibrinogen-binding protein (Efb).

The secreted Staphylococcus aureus extracellular fibrinogen-binding protein (Efb) is a virulence factor that binds to both the complement component C3b and fibrinogen. Our laboratory previously reported that by binding to C3b, Efb inhibited complement activation and blocked opsonophagocytosis. We have now located the Efb binding domain in C3b to the C3d fragment and determined a disassociation ...

Mutational analyses reveal that the staphylococcal immune evasion molecule Sbi and complement receptor 2 (CR2) share overlapping contact residues on C3d: implications for the controversy regarding the CR2/C3d cocrystal structure.

We recently characterized an interaction between the Staphylococcus aureus immune evasion molecule Staphylococcus aureus binder of Ig (Sbi) and complement C3, an interaction mediated primarily through the binding of C3d(g) to Sbi domain IV. Events related to these studies prompted us to investigate via mutagenesis the binding interface of C3d for Sbi domain IV (Sbi-IV), as well as to revisit th...

Electrostatic contributions drive the interaction between Staphylococcus aureus protein Efb-C and its complement target C3d.

The C3-inhibitory domain of Staphylococcus aureus extracellular fibrinogen-binding protein (Efb-C) defines a novel three-helix bundle motif that regulates complement activation. Previous crystallographic studies of Efb-C bound to its cognate subdomain of human C3 (C3d) identified Arg-131 and Asn-138 of Efb-C as key residues for its activity. In order to characterize more completely the physical...

Efb blocks interaction between P-selectin and PSGL-1 1 Extracellular Fibrinogen Binding Protein (Efb) from Staphylococcus aureus Inhibits the Formation of Platelet–Leukocyte Complexes

Extracellular fibrinogen binding protein (Efb) from Staphylococcus aureus inhibits platelet activation, although its mechanism of action has not been established. In this study we discovered that the N-terminal region of Efb (Efb-N) promotes platelet binding of fibrinogen and that Efb-N binding to platelets proceeds via two independent mechanisms: fibrinogen-mediated and fibrinogen-independent....