Fig. 1. Structure of inactive full-length integrin αIIbβ3.

a The overall unsharpened cryo-EM map at 3.4 Å resolution is shown with ribbon diagrams for the αIIb chain (light blue) and β3 chain (orange-red) here and in subsequent figures. The molecule is oriented with the extracellular side of the membrane facing up. The αIIb and β3 domains and the α-genu are labeled in the respective color, except for the hybrid and EGF1-4 domains of β3. b, c The same figure in a rotated by −90° and 180°, respectively. All the 12 subdomains of the ectodomain are resolved, and the two TM α-helices are clearly visualized. d, e Closeup of the cryo-EM density of the metal ions (spheres) at LIMBS (gray), MIDAS (cyan), and ADMIDAS (magenta) of the βA domain (d), the four metal ions (in green spheres) at the bottom of the propeller (e) and the one at the α-genu (e, inset). f Closeup view of the map for glycans at N⁹⁹ and N³⁷¹ of the hybrid domain. g Closeup of residues 419–422 of the propeller domain showing the fit into the EM density.