Location of the binding site. (A) The 5 residues involved in fibrinogen binding to FGF-2 are shown in yellow. (B) Structure of FGF-2 in the fibrinogen binding region. Portions of the crystal structure of FGF-2 are shown with the 5 residues in FGF-2 related to fibrinogen binding indicated in yellow. Positively charged residues are shown in blue and negatively charged residues in red. Approximate distances are: Ser100 to Agn102, 0.54 nM; Ser100 to Arg109, 2.06 nM. (C) Comparison of structure of FGF-1 with that of FGF-2 in the fibrinogen binding region. The residues in FGF-1 corresponding to the 5 residues in FGF-2 involved in fibrinogen binding are shown in yellow. Other positively charged residues are shown in blue and negatively charged residues in red. The location of 2 additional residues in FGF-1 with no corresponding counterparts in FGF-2 (Glu99 and Lys100) are also indicated. Based on published crystal structures.^26-30