Molecule of the Month: Integrin
Integrins forge flexible linkages between the infrastructure inside and outside of cells
![Inactive conformation of integrin. The membrane is shown schematically in gray.](https://cdn.rcsb.org/pdb101/motm/134/mom134_1jv2-2k9j-1m8o.jpg)
Introduction
Linking Cells
Structures by Parts
![Inactive conformation of integrin (left) and a hypothetical model of the open, active form (right), with a fibrinogen peptide in red and a talin domain in magenta.](https://cdn.rcsb.org/pdb101/motm/134/mom134_integrins.jpg)
Integrin Activation
Molecular Dialog
Exploring the Structure
Integrin Motion (PDB entries 3fcs and 2vdo)
![](https://cdn.rcsb.org/pdb101/motm/134/mom134_integrin-jmol.jpg)
Researchers have not been able to crystallize the entire extracellular portion in the open, active form, but they have studied a smaller fragment, which includes just the domains near the binding site. PDB entry 2vdo shows it in the open, active state, bound to a short peptide from fibrinogen. Click on the image to get an interactive Jmol image that allows you to compare the open and closed structures.
Topics for Further Discussion
- Researchers have studied the interaction of integrins with different molecules inside and outside cells. Can you find structures that show these interactions?
- The structure of a snake toxin that attacks integrin is available in PDB entry 1v7p. Why would blocking integrins make a snake toxin more effective?
Related PDB-101 Resources
- Browse Molecular Infrastructure
References
- S. J. Shattil, C. Kim and M. H. Ginsberg (2010) The final steps of integrin activation: the end game. Nature Reviews Cell and Molecular Biology 11, 288-300.
- M. A. Arnaout, S. L. Goodman and J.-P. Xiong (2007) Structure and mechanics of integrin-based cell adhesion. Current Opinion in Cell Biology 19, 495-507.
- B.-H. Luo, C. V. Carman and T. A. Springer (2007) Structural basis of integrin regulation and signaling. Annual Review of Immunology 25, 619-47.
- B.-H. Luo and T. A. Springer (2006) Integrin structures and conformational signaling. Current Opinion in Cell Biology 18, 579-586.
February 2011, David Goodsell
http://doi.org/10.2210/rcsb_pdb/mom_2011_2