2oz4: Difference between revisions
New page: left|200px<br /> <applet load="2oz4" size="450" color="white" frame="true" align="right" spinBox="true" caption="2oz4, resolution 2.70Å" /> '''Structural Plastici... |
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[[Image:2oz4.gif|left|200px]]<br /> | [[Image:2oz4.gif|left|200px]]<br /><applet load="2oz4" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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'''Structural Plasticity in IgSF Domain 4 of ICAM-1 Mediates Cell Surface Dimerization'''<br /> | '''Structural Plasticity in IgSF Domain 4 of ICAM-1 Mediates Cell Surface Dimerization'''<br /> | ||
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==Overview== | ==Overview== | ||
The Ig superfamily (IgSF) intercellular adhesion molecule-1 (ICAM-1), equilibrates between monomeric and dimeric forms on the cell surface, and, dimerization enhances cell adhesion. A crystal structure of ICAM-1 IgSF, domains (D) 3-5 revealed a unique dimerization interface in which D4s of, two protomers fuse through edge beta-strands to form a single super, beta-sandwich domain. Here, we describe a crystal structure at 2.7-A, resolution of monomeric ICAM-1 D3-D5, stabilized by the monomer-specific, Fab CA7. CA7 binds to D5 in a region that is buried in the dimeric, interface and is distal from the dimerization site in D4. In monomeric, ICAM-1 D3-D5, a 16-residue loop in D4 that is disordered in the dimeric, structure could clearly be traced as a BC loop, a short C strand, and a CE, meander with a cis-Pro followed by a solvent-exposed, flexible, four-residue region. Deletions of 6 or 10 residues showed that the, C-strand is essential for monomer stability, whereas a distinct, six-residue deletion showed little contribution of the CE meander., Mutation of two inward-pointing Leu residues in edge beta-strand E to Lys, increased monomer stability, confirming the hypothesis that, inward-pointing charged side chains on edge beta-strands are an important, design feature to prevent beta-supersheet formation. Overall, the studies, reveal that monomer-dimer transition is associated with a surprisingly, large, physiologically relevant, IgSF domain rearrangement. | The Ig superfamily (IgSF) intercellular adhesion molecule-1 (ICAM-1), equilibrates between monomeric and dimeric forms on the cell surface, and, dimerization enhances cell adhesion. A crystal structure of ICAM-1 IgSF, domains (D) 3-5 revealed a unique dimerization interface in which D4s of, two protomers fuse through edge beta-strands to form a single super, beta-sandwich domain. Here, we describe a crystal structure at 2.7-A, resolution of monomeric ICAM-1 D3-D5, stabilized by the monomer-specific, Fab CA7. CA7 binds to D5 in a region that is buried in the dimeric, interface and is distal from the dimerization site in D4. In monomeric, ICAM-1 D3-D5, a 16-residue loop in D4 that is disordered in the dimeric, structure could clearly be traced as a BC loop, a short C strand, and a CE, meander with a cis-Pro followed by a solvent-exposed, flexible, four-residue region. Deletions of 6 or 10 residues showed that the, C-strand is essential for monomer stability, whereas a distinct, six-residue deletion showed little contribution of the CE meander., Mutation of two inward-pointing Leu residues in edge beta-strand E to Lys, increased monomer stability, confirming the hypothesis that, inward-pointing charged side chains on edge beta-strands are an important, design feature to prevent beta-supersheet formation. Overall, the studies, reveal that monomer-dimer transition is associated with a surprisingly, large, physiologically relevant, IgSF domain rearrangement. | ||
==About this Structure== | ==About this Structure== | ||
2OZ4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with NAG, SO4, ZN and TRS as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 2OZ4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OZ4 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: structural plasticity]] | [[Category: structural plasticity]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 12:53:33 2008'' | ||
Revision as of 13:53, 23 January 2008
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Structural Plasticity in IgSF Domain 4 of ICAM-1 Mediates Cell Surface Dimerization
OverviewOverview
The Ig superfamily (IgSF) intercellular adhesion molecule-1 (ICAM-1), equilibrates between monomeric and dimeric forms on the cell surface, and, dimerization enhances cell adhesion. A crystal structure of ICAM-1 IgSF, domains (D) 3-5 revealed a unique dimerization interface in which D4s of, two protomers fuse through edge beta-strands to form a single super, beta-sandwich domain. Here, we describe a crystal structure at 2.7-A, resolution of monomeric ICAM-1 D3-D5, stabilized by the monomer-specific, Fab CA7. CA7 binds to D5 in a region that is buried in the dimeric, interface and is distal from the dimerization site in D4. In monomeric, ICAM-1 D3-D5, a 16-residue loop in D4 that is disordered in the dimeric, structure could clearly be traced as a BC loop, a short C strand, and a CE, meander with a cis-Pro followed by a solvent-exposed, flexible, four-residue region. Deletions of 6 or 10 residues showed that the, C-strand is essential for monomer stability, whereas a distinct, six-residue deletion showed little contribution of the CE meander., Mutation of two inward-pointing Leu residues in edge beta-strand E to Lys, increased monomer stability, confirming the hypothesis that, inward-pointing charged side chains on edge beta-strands are an important, design feature to prevent beta-supersheet formation. Overall, the studies, reveal that monomer-dimer transition is associated with a surprisingly, large, physiologically relevant, IgSF domain rearrangement.
About this StructureAbout this Structure
2OZ4 is a Single protein structure of sequence from Homo sapiens and Mus musculus with , , and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Structural plasticity in Ig superfamily domain 4 of ICAM-1 mediates cell surface dimerization., Chen X, Kim TD, Carman CV, Mi LZ, Song G, Springer TA, Proc Natl Acad Sci U S A. 2007 Sep 25;104(39):15358-63. Epub 2007 Sep 19. PMID:17881562
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