Download MendeleyStructural insights into integrin alpha 5 beta 1 opening by fibronectin ligand.
Schumacher, S., Dedden, D., Nunez, R.V., Matoba, K., Takagi, J., Biertumpfel, C., Mizuno, N.(2021) Sci Adv 7
- PubMed: 33962943
- DOI: https://doi.org/10.1126/sciadv.abe9716
- Primary Citation of Related Structures:
7NWL, 7NXD - PubMed Abstract:
Integrin α 5 β 1 is a major fibronectin receptor critical for cell migration. Upon complex formation, fibronectin and α 5 β 1 undergo conformational changes. While this is key for cell-tissue connections, its mechanism is unknown. Here, we report cryo-electron microscopy structures of native human α 5 β 1 with fibronectin to 3.1-angstrom resolution, and in its resting state to 4.6-angstrom resolution. The α 5 β 1 -fibronectin complex revealed simultaneous interactions at the arginine-glycine-aspartate loop, the synergy site, and a newly identified binding site proximal to adjacent to metal ion-dependent adhesion site, inducing the translocation of helix α1 to secure integrin opening. Resting α 5 β 1 adopts an incompletely bent conformation, challenging the model of integrin sharp bending inhibiting ligand binding. Our biochemical and structural analyses showed that affinity of α 5 β 1 for fibronectin is increased with manganese ions (Mn 2+ ) while adopting the half-bent conformation, indicating that ligand-binding affinity does not depend on conformation, and α 5 β 1 opening is induced by ligand-binding.
Organizational Affiliation:
Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D-82152 Martinsried, Germany.
