1zon
From Proteopedia
(New page: 200px<br /> <applet load="1zon" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zon, resolution 2.0Å" /> '''CD11A I-DOMAIN WITHO...) |
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| - | [[Image:1zon.gif|left|200px]]<br /> | + | [[Image:1zon.gif|left|200px]]<br /><applet load="1zon" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1zon" size=" | + | |
caption="1zon, resolution 2.0Å" /> | caption="1zon, resolution 2.0Å" /> | ||
'''CD11A I-DOMAIN WITHOUT BOUND CATION'''<br /> | '''CD11A I-DOMAIN WITHOUT BOUND CATION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: The integrin family of cell-surface receptors mediates a wide | + | BACKGROUND: The integrin family of cell-surface receptors mediates a wide variety of cell-cell and cell-extracellular matrix interactions. Integrin-ligand interactions are invariably dependent on the presence of divalent cations, and a subset of integrins contain a approximately 200 amino acid inserted (I) domain that is important for ligand binding activity and contains a single divalent cation binding site. Many integrins are believed to respond to stimuli by undergoing a conformational change that increases their affinity for ligand, and there is a clear difference between two crystal structures of the CD11b I domain with different divalent cations (magnesium and manganese) bound. In addition to the different bound cation, a 'ligand mimetic' crystal lattice interaction in the CD11b I domain structure with bound magnesium has led to the interpretation that the different CD11b I domain structures represent different affinity states of I domains. The influence of the bound cation on I domain structure and function remains incompletely understood, however. The crystal structure of the CD11a I domain bound to manganese is known. We therefore set out to determine whether this structure changes when the metal ion is altered or removed. RESULTS: We report here the crystal structures of the CD11a I domain determined in the absence of bound metal ion and with bound magnesium ion. No major structural rearrangements are observed in the metal-binding site of the CD11a I domain in the absence or presence of bound manganese ion. The structures of the CD11a I domain with magnesium or manganese bound are extremely similar. CONCLUSIONS: The conformation of the CD11a I domain is not altered by changes in metal ion binding. The cation-dependence of ligand binding thus indicates that the metal ion is either involved in direct interaction with ligand or required to promote a favorable quaternary arrangement of the integrin. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZON 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:// | + | 1ZON 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=1ZON OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Leahy, D | + | [[Category: Leahy, D J.]] |
[[Category: Qu, A.]] | [[Category: Qu, A.]] | ||
[[Category: cell adhesion]] | [[Category: cell adhesion]] | ||
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[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:17:41 2008'' |
Revision as of 14:17, 21 February 2008
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CD11A I-DOMAIN WITHOUT BOUND CATION
Overview
BACKGROUND: The integrin family of cell-surface receptors mediates a wide variety of cell-cell and cell-extracellular matrix interactions. Integrin-ligand interactions are invariably dependent on the presence of divalent cations, and a subset of integrins contain a approximately 200 amino acid inserted (I) domain that is important for ligand binding activity and contains a single divalent cation binding site. Many integrins are believed to respond to stimuli by undergoing a conformational change that increases their affinity for ligand, and there is a clear difference between two crystal structures of the CD11b I domain with different divalent cations (magnesium and manganese) bound. In addition to the different bound cation, a 'ligand mimetic' crystal lattice interaction in the CD11b I domain structure with bound magnesium has led to the interpretation that the different CD11b I domain structures represent different affinity states of I domains. The influence of the bound cation on I domain structure and function remains incompletely understood, however. The crystal structure of the CD11a I domain bound to manganese is known. We therefore set out to determine whether this structure changes when the metal ion is altered or removed. RESULTS: We report here the crystal structures of the CD11a I domain determined in the absence of bound metal ion and with bound magnesium ion. No major structural rearrangements are observed in the metal-binding site of the CD11a I domain in the absence or presence of bound manganese ion. The structures of the CD11a I domain with magnesium or manganese bound are extremely similar. CONCLUSIONS: The conformation of the CD11a I domain is not altered by changes in metal ion binding. The cation-dependence of ligand binding thus indicates that the metal ion is either involved in direct interaction with ligand or required to promote a favorable quaternary arrangement of the integrin.
About this Structure
1ZON is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The role of the divalent cation in the structure of the I domain from the CD11a/CD18 integrin., Qu A, Leahy DJ, Structure. 1996 Aug 15;4(8):931-42. PMID:8805579
Page seeded by OCA on Thu Feb 21 16:17:41 2008
