Download MendeleyStructures of the aL I domain and its complex with ICAM-1 reveal a shape-shifting pathway for integrin regulation
Shimaoka, M., Xiao, T., Liu, J.-H., Yang, Y., Dong, Y., Jun, C.-D., McCormack, A., Zhang, R., Joachimiak, A., Takagi, J., Wang, J.-H., Springer, T.A.(2003) Cell 112: 99-111
- PubMed: 12526797
- DOI: https://doi.org/10.1016/s0092-8674(02)01257-6
- Primary Citation of Related Structures:
1MJN, 1MQ8, 1MQ9, 1MQA - PubMed Abstract:
The structure of the I domain of integrin alpha L beta 2 bound to the Ig superfamily ligand ICAM-1 reveals the open ligand binding conformation and the first example of an integrin-IgSF interface. The I domain Mg2+ directly coordinates Glu-34 of ICAM-1, and a dramatic swing of I domain residue Glu-241 enables a critical salt bridge. Liganded and unliganded structures for both high- and intermediate-affinity mutant I domains reveal that ligand binding can induce conformational change in the alpha L I domain and that allosteric signals can convert the closed conformation to intermediate or open conformations without ligand binding. Pulling down on the C-terminal alpha 7 helix with introduced disulfide bonds ratchets the beta 6-alpha 7 loop into three different positions in the closed, intermediate, and open conformations, with a progressive increase in affinity.
Organizational Affiliation:
The Center for Blood Research, Department of Pathology, Department of Anesthesia, Department of Pediatrics, Boston, Massachusetts 02115.
