|3at0, resolution 2.50Å ()|
|Gene:||clfB, SA2423 (Staphylococcus aureus)|
Structural and biochemical characterization of ClfB:ligand interactions
Clumping factor B (ClfB) from Staphylococcus aureus is a bifunctional protein that binds to human cytokeratin 10 (K10) and fibrinogen (Fg). ClfB has been implicated in S. aureus colonization of nasal epithelium and is therefore a key virulence factor. People colonized with S. aureus are at an increased risk for invasive staphylococcal disease. In this study, we have determined the crystal structures of the ligand-binding region of ClfB in an apo-form and in complex with human K10 and Fg alpha-chain-derived peptides, respectively. We have determined the structures of MSCRAMM binding to two ligands with different sequences in the same site showing the versatile nature of the ligand recognition mode of microbial surface components recognizing adhesive matrix molecules. Both ligands bind ClfB by parallel beta-sheet complementation as observed for the clumping factor A.gamma-chain peptide complex. The beta-sheet complementation is shorter in the ClfB.Fg alpha-chain peptide complex. The structures show that several residues in ClfB are important for binding to both ligands, whereas others only make contact with one of the ligands. A common motif GSSGXG found in both ligands is part of the ClfB-binding site. This motif is found in many human proteins thus raising the possibility that ClfB recognizes additional ligands.
Structural and biochemical characterization of Staphylococcus aureus clumping factor B/ligand interactions., Ganesh VK, Barbu EM, Deivanayagam CC, Le B, Anderson AS, Matsuka YV, Lin SL, Foster TJ, Narayana SV, Hook M, J Biol Chem. 2011 Jul 22;286(29):25963-72. Epub 2011 May 3. PMID:021543319
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
[FIBA_HUMAN] Defects in FGA are a cause of congenital afibrinogenemia (CAFBN) [MIM:202400]. This is a rare autosomal recessive disorder characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen. Note=The majority of cases of afibrinogenemia are due to truncating mutations. Variations in position Arg-35 (the site of cleavage of fibrinopeptide a by thrombin) leads to alpha-dysfibrinogenemias. Defects in FGA are a cause of amyloidosis type 8 (AMYL8) [MIM:105200]; also known as systemic non-neuropathic amyloidosis or Ostertag-type amyloidosis. AMYL8 is a hereditary generalized amyloidosis due to deposition of apolipoprotein A1, fibrinogen and lysozyme amyloids. Viscera are particularly affected. There is no involvement of the nervous system. Clinical features include renal amyloidosis resulting in nephrotic syndrome, arterial hypertension, hepatosplenomegaly, cholestasis, petechial skin rash.
[CLFB_STAAN] Cell surface-associated protein implicated in virulence by promoting bacterial attachment to both alpha- and beta-chains of human fibrinogen and inducing the formation of bacterial clumps (By similarity). [FIBA_HUMAN] Fibrinogen has a double function: yielding monomers that polymerize into fibrin and acting as a cofactor in platelet aggregation.