1N3Y

Crystal structure of the alpha-X beta2 integrin I domain

Summary for 1N3Y

• Entry DOI: 10.2210/pdb1n3y/pdb
• Descriptor: Integrin alpha-X (2 entities in total)
• Functional Keywords: alpha/beta rossmann fold, cell adhesion
• Biological source: Homo sapiens (human)
• Cellular location: Membrane; Single-pass type I membrane protein: P20702
• Total number of polymer chains: 1
• Total formula weight: 22355.28

Authors

Vorup-Jensen, T.,Ostermeier, C.,Shimaoka, M.,Hommel, U.,Springer, T.A. (deposition date: 2002-10-30, release date: 2003-02-18, Last modification date: 2024-04-03)

Primary citation

Vorup-Jensen, T.,Ostermeier, C.,Shimaoka, M.,Hommel, U.,Springer, T.A.
Structure and allosteric regulation of the alpha X beta 2 integrin I domain.
Proc.Natl.Acad.Sci.USA, 100:1873-1878, 2003

PubMed Abstract: The integrin alpha X beta 2 (CD11c/CD18, p150,95) binds ligands through the I domain of the alpha X subunit. Ligands include the complement factor fragment iC3b, a key component in the innate immune defense, which, together with the expression of alpha X beta 2 on dendritic cells and on other leukocytes, suggests a role in the immune response. We now report the structure of the alpha X I domain resolved at 1.65 A by x-ray crystallography. To analyze structural requirements for ligand binding we made a mutation in the alpha X I domain C-terminal helix, which increased the affinity for iC3b approximately 200-fold to 2.4 microM compared with the wild-type domain affinity of approximately 400 microM. Gel permeation chromatography supported a conformational change between the wild-type and mutated domains. Conservation of allosteric regulation in the alpha X I domain points to the functional importance of this phenomenon.

PubMed: 12554829
DOI: 10.1073/pnas.0237387100

Experimental method

X-RAY DIFFRACTION (1.65 Å)