Domain organization of kindlin-3 in the monomer and homotrimer conformation. (A) Domain organization of kindlin-3. Kindlin-3 contains a FERM domain consisting of F0, F1, F2, and F3 subdomains. F1 domain contains a long unstructured loop comprising 83 residues. A pleckstrin homology (PH) domain is inserted in the F2. (B) Crystal structure of kindlin-3 monomer. The kindlin-3 adopts a FERM domain cloverleaf-like conformation. (C) Crystal structure of the kindlin-3 homotrimer. Kindlin-3 PH domain interacts with the F3 subdomain of another kindlin-3 molecule, thereby masking the integrin binding site of kindlin-3. Panels B and C are adapted from Bu et al.⁵¹