4b60
Structure of rFnBPA(189-505) in complex with fibrinogen gamma chain C- terminal peptide
Structural highlights
FunctionFNBA_STAA8 Possesses multiple, substituting fibronectin (Fn) binding regions, each capable of conferring adherence to both soluble and immobilized forms of Fn. This confers to S.aureus the ability to invade endothelial cells both in vivo and in vitro, without requiring additional factors, although in a slow and inefficient way through actin rearrangements in host cells. This invasion process is mediated by integrin alpha-5/beta-1. Promotes bacterial attachment to both soluble and immobilized forms of fibrinogen (Fg) by means of a unique binding site localized within the 17 C-terminal residues of the gamma-chain of human Fg. Both plasma proteins (Fn and Fg) function as a bridge between bacterium and host cell. Promotes attachment to immobilized elastin peptides in a dose-dependent and saturable manner. Promotes attachment to both full-length and segments of immobilized human tropoelastin at multiple sites in a dose and pH-dependent manner. Promotes adherence to and aggregation of activated platelets independently of other S.aureus surface molecules. Is a critical mediator implicated in the induction of experimental endocarditis in rats with catheter-induced aortic vegetations, promoting both colonization and persistence of the bacterium into the host.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedThe adjacent fibrinogen (Fg)- and fibronectin (Fn)- binding sites on Fn-binding protein A (FnBPA), a cell-surface protein from Staphylococcus aureus, are implicated in the initiation and persistence of infection. FnBPA contains a single Fg-binding site (that also binds elastin) and multiple Fn-binding sites. Here, we solved the structure of the N2N3 domains containing the Fg-binding site of FnBPA in the apo-form and in complex with a Fg-peptide. The Fg-binding mechanism is similar to that of homologous bacterial proteins but without the requirement for latch strand residues. We show that the Fg- and the most N-terminal Fn-binding sites are non-overlapping but in close proximity. While Fg and a sub-domain of Fn can form a ternary complex on an FnBPA protein construct containing a Fg- and single Fn-binding site, binding of intact Fn appears to inhibit Fg binding, suggesting steric regulation. Given the concentrations of Fn and Fg in the plasma, this mechanism might result in targeting of S. aureus to fibrin-rich thrombi or elastin-rich tissues. Evidence for Steric Regulation of Fibrinogen binding to Staphylococcus aureus fibronectin-binding protein A (FnBPA).,Stemberk V, Jones RP, Moroz O, Atkin KE, Edwards AM, Turkenburg JP, Leech AP, Massey RC, Potts JR J Biol Chem. 2014 Mar 13. PMID:24627488[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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