Fig. 6.

The putative ligand-binding site at the integrin αβ interface. GRASP representation of the αV propeller (white) and the α3 A-domain (gray), viewed from the top of the head (the tails lying in the back). Arg¹⁴³–Phe¹⁵⁴ (red) and Gly¹⁷²–Gly¹⁸¹ (green) of αV correspond to the identified ligand-binding residues Arg¹⁴⁷–Tyr¹⁶⁶ and Gly¹⁸⁴–Gly¹⁹³, respectively, in αIIb. Ligand-binding residues in β3 (Asp¹⁷⁹–Thr¹⁸³, “ligand specificity” region (magenta); Asp¹¹⁹, Ser¹²¹, Ser¹²³, Glu²²⁰ (all MIDAS residues), and Arg²¹⁴ (yellow) are shown. Asp²¹⁷ in β3 (also in yellow) is involved in binding of a ligand-mimetic monoclonal antibody. The expected MIDAS metal ion is in blue.