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1zxq
From Proteopedia
(New page: 200px<br /> <applet load="1zxq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zxq, resolution 2.2Å" /> '''THE CRYSTAL STRUCTUR...) |
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| - | [[Image:1zxq.gif|left|200px]]<br /> | + | [[Image:1zxq.gif|left|200px]]<br /><applet load="1zxq" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1zxq" size=" | + | |
caption="1zxq, resolution 2.2Å" /> | caption="1zxq, resolution 2.2Å" /> | ||
'''THE CRYSTAL STRUCTURE OF ICAM-2'''<br /> | '''THE CRYSTAL STRUCTURE OF ICAM-2'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Recognition by integrin proteins on the cell surface regulates the | + | Recognition by integrin proteins on the cell surface regulates the adhesive interactions between cells and their surroundings. The structure of the 'I' domain that is found in some but not all integrins, has been determined. However, the only integrin ligands for which structures are known, namely fibronectin and VCAM-1, are recognized by integrins that lack I domains. The intercellular adhesion molecules ICAM-1, 2 and 3 are, like VCAM-1, members of the immunoglobulin superfamily (IgSF), but they are recognized by an I domain-containing integrin, lymphocyte-function-associated antigen 1 (LFA-1, or CD11a/CD18). Here we present the crystal structure of the extracellular region of ICAM-2. The glutamic acid residue at position 37 is critical for LFA-1 binding and is proposed to coordinate the Mg2+ ion in the I domain; this Glu 37 is surrounded by a relatively flat recognition surface and lies in a beta-strand, whereas the critical aspartic acid residue in VCAM-1 and fibronectin lie in protruding loops. This finding suggests that there are differences in the architecture of recognition sites between integrins that contain or lack I domains. A bend between domains 1 and 2 of ICAM-2 and a tripod-like arrangement of N-linked glycans in the membrane-proximal region of domain 2 may be important for presenting the recognition surface to LFA-1. A model of ICAM-1 based on the ICAM-2 structure provides a framework for understanding its recognition by pathogens. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZXQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1ZXQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZXQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Casasnovas, J | + | [[Category: Casasnovas, J M.]] |
| - | [[Category: Harrison, S | + | [[Category: Harrison, S C.]] |
| - | [[Category: Springer, T | + | [[Category: Springer, T A.]] |
| - | [[Category: Wang, J | + | [[Category: Wang, J H.]] |
[[Category: cell adhesion]] | [[Category: cell adhesion]] | ||
[[Category: glycoprotein]] | [[Category: glycoprotein]] | ||
| Line 25: | Line 24: | ||
[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:20:06 2008'' |
Revision as of 14:20, 21 February 2008
|
THE CRYSTAL STRUCTURE OF ICAM-2
Overview
Recognition by integrin proteins on the cell surface regulates the adhesive interactions between cells and their surroundings. The structure of the 'I' domain that is found in some but not all integrins, has been determined. However, the only integrin ligands for which structures are known, namely fibronectin and VCAM-1, are recognized by integrins that lack I domains. The intercellular adhesion molecules ICAM-1, 2 and 3 are, like VCAM-1, members of the immunoglobulin superfamily (IgSF), but they are recognized by an I domain-containing integrin, lymphocyte-function-associated antigen 1 (LFA-1, or CD11a/CD18). Here we present the crystal structure of the extracellular region of ICAM-2. The glutamic acid residue at position 37 is critical for LFA-1 binding and is proposed to coordinate the Mg2+ ion in the I domain; this Glu 37 is surrounded by a relatively flat recognition surface and lies in a beta-strand, whereas the critical aspartic acid residue in VCAM-1 and fibronectin lie in protruding loops. This finding suggests that there are differences in the architecture of recognition sites between integrins that contain or lack I domains. A bend between domains 1 and 2 of ICAM-2 and a tripod-like arrangement of N-linked glycans in the membrane-proximal region of domain 2 may be important for presenting the recognition surface to LFA-1. A model of ICAM-1 based on the ICAM-2 structure provides a framework for understanding its recognition by pathogens.
About this Structure
1ZXQ is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystal structure of ICAM-2 reveals a distinctive integrin recognition surface., Casasnovas JM, Springer TA, Liu JH, Harrison SC, Wang JH, Nature. 1997 May 15;387(6630):312-5. PMID:9153399
Page seeded by OCA on Thu Feb 21 16:20:06 2008
