1ves: Difference between revisions
New page: left|200px<br /><applet load="1ves" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ves, resolution 2.18Å" /> '''Structure of New Ant... |
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[[Image:1ves.jpg|left|200px]]<br /><applet load="1ves" size=" | [[Image:1ves.jpg|left|200px]]<br /><applet load="1ves" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1ves, resolution 2.18Å" /> | caption="1ves, resolution 2.18Å" /> | ||
'''Structure of New Antigen Receptor variable domain from sharks'''<br /> | '''Structure of New Antigen Receptor variable domain from sharks'''<br /> | ||
==Overview== | ==Overview== | ||
The Ig new antigen receptors (IgNARs) are single-domain antibodies found | The Ig new antigen receptors (IgNARs) are single-domain antibodies found in the serum of sharks. Here, we report 2.2- and 2.8-A structures of the type 2 IgNAR variable domains 12Y-1 and 12Y-2. Structural features include, first, an Ig superfamily topology transitional between cell adhesion molecules, antibodies, and T cell receptors; and, second, a vestigial complementarity-determining region 2 at the "bottom" of the molecule, apparently discontinuous from the antigen-binding paratope and similar to that observed in cell adhesion molecules. Thus, we suggest that IgNARs originated as cell-surface adhesion molecules coopted to the immune repertoire and represent an evolutionary lineage independent of variable heavy chain/variable light chain type antibodies. Additionally, both 12Y-1 and 12Y-2 form unique crystallographic dimers, predominantly mediated by main-chain framework interactions, which represent a possible model for primordial cell-based interactions. Unusually, the 12Y-2 complementarity-determining region 3 also adopts an extended beta-hairpin structure, suggesting a distinct selective advantage in accessing cryptic antigenic epitopes. | ||
==About this Structure== | ==About this Structure== | ||
1VES is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Orectolobus_maculatus Orectolobus maculatus]. Full crystallographic information is available from [http:// | 1VES is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Orectolobus_maculatus Orectolobus maculatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VES OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Orectolobus maculatus]] | [[Category: Orectolobus maculatus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streltsov, V | [[Category: Streltsov, V A.]] | ||
[[Category: 12y-2]] | [[Category: 12y-2]] | ||
[[Category: ig vnar]] | [[Category: ig vnar]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:34:31 2008'' | ||
Revision as of 13:34, 21 February 2008
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Structure of New Antigen Receptor variable domain from sharks
Overview
The Ig new antigen receptors (IgNARs) are single-domain antibodies found in the serum of sharks. Here, we report 2.2- and 2.8-A structures of the type 2 IgNAR variable domains 12Y-1 and 12Y-2. Structural features include, first, an Ig superfamily topology transitional between cell adhesion molecules, antibodies, and T cell receptors; and, second, a vestigial complementarity-determining region 2 at the "bottom" of the molecule, apparently discontinuous from the antigen-binding paratope and similar to that observed in cell adhesion molecules. Thus, we suggest that IgNARs originated as cell-surface adhesion molecules coopted to the immune repertoire and represent an evolutionary lineage independent of variable heavy chain/variable light chain type antibodies. Additionally, both 12Y-1 and 12Y-2 form unique crystallographic dimers, predominantly mediated by main-chain framework interactions, which represent a possible model for primordial cell-based interactions. Unusually, the 12Y-2 complementarity-determining region 3 also adopts an extended beta-hairpin structure, suggesting a distinct selective advantage in accessing cryptic antigenic epitopes.
About this Structure
1VES is a Single protein structure of sequence from Orectolobus maculatus. Full crystallographic information is available from OCA.
Reference
Structural evidence for evolution of shark Ig new antigen receptor variable domain antibodies from a cell-surface receptor., Streltsov VA, Varghese JN, Carmichael JA, Irving RA, Hudson PJ, Nuttall SD, Proc Natl Acad Sci U S A. 2004 Aug 24;101(34):12444-9. Epub 2004 Aug 10. PMID:15304650
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