1n3y
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The integrin alpha X beta 2 (CD11c/CD18, p150,95) binds ligands through | + | 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. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Ostermeier, C.]] | [[Category: Ostermeier, C.]] | ||
[[Category: Shimaoka, M.]] | [[Category: Shimaoka, M.]] | ||
| - | [[Category: Springer, T | + | [[Category: Springer, T A.]] |
[[Category: Vorup-Jensen, T.]] | [[Category: Vorup-Jensen, T.]] | ||
[[Category: alpha/beta rossmann fold]] | [[Category: alpha/beta rossmann fold]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:01:58 2008'' |
Revision as of 12:02, 21 February 2008
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Crystal structure of the alpha-X beta2 integrin I domain
Overview
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.
About this Structure
1N3Y is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structure and allosteric regulation of the alpha X beta 2 integrin I domain., Vorup-Jensen T, Ostermeier C, Shimaoka M, Hommel U, Springer TA, Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1873-8. Epub 2003 Jan 28. PMID:12554829
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