1MQ9

Crystal structure of high affinity alphaL I domain with ligand mimetic crystal contact

Summary for 1MQ9

• Entry DOI: 10.2210/pdb1mq9/pdb
• Related: 1MQ8 1MQA
• Descriptor: Integrin alpha-L, MANGANESE (II) ION (3 entities in total)
• Functional Keywords: designed disulfide bridge, rossmann fold, metal mediated protein interface, immune system
• Biological source: Homo sapiens (human)
• Cellular location: Membrane; Single-pass type I membrane protein: P20701
• Total number of polymer chains: 1
• Total formula weight: 20550.44

Authors

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. (deposition date: 2002-09-15, release date: 2003-01-14, Last modification date: 2024-10-30)

Primary citation

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.
Structures of the aL I domain and its complex with ICAM-1 reveal a shape-shifting pathway for integrin regulation
Cell(Cambridge,Mass.), 112:99-111, 2003

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.

PubMed: 12526797
DOI: 10.1016/S0092-8674(02)01257-6

Experimental method

X-RAY DIFFRACTION (2 Å)