3K6S

Structure of integrin alphaXbeta2 ectodomain

Summary for 3K6S

• Entry DOI: 10.2210/pdb3k6s/pdb
• Related: 3K71 3K72
• Descriptor: Integrin alpha-X, Integrin beta-2, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (10 entities in total)
• Functional Keywords: integrin, cell receptor, adhesion molecule, cell adhesion, pyrrolidone carboxylic acid
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 8
• Total formula weight: 796008.50

Authors

Xie, C.,Zhu, J.,Chen, X.,Mi, L.,Nishida, N.,Springer, T.A. (deposition date: 2009-10-09, release date: 2010-01-12, Last modification date: 2024-10-16)

Primary citation

Xie, C.,Zhu, J.,Chen, X.,Mi, L.,Nishida, N.,Springer, T.A.
Structure of an integrin with an alphaI domain, complement receptor type 4.
Embo J., 29:666-679, 2010

PubMed Abstract: We report the structure of an integrin with an alphaI domain, alpha(X)beta(2), the complement receptor type 4. It was earlier expected that a fixed orientation between the alphaI domain and the beta-propeller domain in which it is inserted would be required for allosteric signal transmission. However, the alphaI domain is highly flexible, enabling two betaI domain conformational states to couple to three alphaI domain states, and greater accessibility for ligand recognition. Although alpha(X)beta(2) is bent similarly to integrins that lack alphaI domains, the terminal domains of the alpha- and beta-legs, calf-2 and beta-tail, are oriented differently than in alphaI-less integrins. Linkers extending to the transmembrane domains are unstructured. Previous mutations in the beta(2)-tail domain support the importance of extension, rather than a deadbolt, in integrin activation. The locations of further activating mutations and antibody epitopes show the critical role of extension, and conversion from the closed to the open headpiece conformation, in integrin activation. Differences among 10 molecules in crystal lattices provide unprecedented information on interdomain flexibility important for modelling integrin extension and activation.

PubMed: 20033057
DOI: 10.1038/emboj.2009.367

Experimental method

X-RAY DIFFRACTION (3.5 Å)