Fig. 3: Exposure of the ligand-binding site in the inactive bent conformation of full-length αIIbβ3.
From: Cryo-EM structures of full-length integrin αIIbβ3 in native lipids
The cryo-EM density map has been fitted with the bound γ-peptide from fibrinogen (as spheres) according to the X-ray structure of the headpiece (2VDR.pdb). The distance measured between the MIDAS metal ion (cyan sphere) and αIIb’s Arg962 at the extracellular leaflet of the membrane (solid vertical line) is 71.5 Å. The calf1-calf2 leg domain axis (dashed line) is tilted from the normal by a 56° angle relative to the plane of the membrane (dotted line). The tilt angle is measured by a chord running from the metal ion at the αIIb genu (green sphere) to Ser913 at the bottom of the calf2 domain (dotted line).
