1jl4
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1iak|1IAK]], [[3cd4|3CD4]], [[1wio|1WIO]], [[1g9m|1G9M]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1jl4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1jl4 OCA], [http://www.ebi.ac.uk/pdbsum/1jl4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1jl4 RCSB]</span> | ||
}} | }} | ||
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[[Category: protein-protein complex]] | [[Category: protein-protein complex]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:35:13 2008'' |
Revision as of 18:35, 30 March 2008
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| , resolution 4.3Å | |||||||
|---|---|---|---|---|---|---|---|
| Related: | 1IAK, 3CD4, 1WIO, 1G9M
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF THE HUMAN CD4 N-TERMINAL TWO DOMAIN FRAGMENT COMPLEXED TO A CLASS II MHC MOLECULE
Overview
The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) class II MHC molecule with associated peptide (pMHCII) shows that only the "top corner" of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both alpha 2 and beta 2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency.
About this Structure
1JL4 is a Protein complex structure of sequences from Gallus gallus, Homo sapiens and Mus musculus. Full crystallographic information is available from OCA.
Reference
Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule., Wang JH, Meijers R, Xiong Y, Liu JH, Sakihama T, Zhang R, Joachimiak A, Reinherz EL, Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10799-804. Epub 2001 Sep 4. PMID:11535811
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