View source for 2i27


==Crystal Structure Analysis of the Nurse Shark New Antigen Receptor Ancestral variable domain==
<StructureSection load='2i27' size='340' side='right'caption='[[2i27]], [[Resolution|resolution]] 1.92&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2i27]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Ginci Ginci]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I27 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2I27 FirstGlance]. <br>
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[2i24|2i24]], [[2i25|2i25]], [[2i26|2i26]]</div></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2i27 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i27 OCA], [https://pdbe.org/2i27 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2i27 RCSB], [https://www.ebi.ac.uk/pdbsum/2i27 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2i27 ProSAT]</span></td></tr>
</table>
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i2/2i27_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2i27 ConSurf].
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== Publication Abstract from PubMed ==
Sharks express an unusual heavy-chain isotype called IgNAR, whose variable regions bind antigen as independent soluble domains. To further probe affinity maturation of the IgNAR response, we structurally characterized the germline and somatically matured versions of a type II variable (V) region, both in the presence and absence of its antigen, hen egg-white lysozyme. Despite a disulfide bond linking complementarity determining regions (CDRs) 1 and 3, both germline and somatically matured V regions displayed significant structural changes in these CDRs upon complex formation with antigen. Somatic mutations in the IgNAR V region serve to increase the number of contacts with antigen, as reflected by a tenfold increase in affinity, and one of these mutations appears to stabilize the CDR3 region. In addition, a residue in the HV4 loop plays an important role in antibody-antigen interaction, consistent with the high rate of somatic mutations in this non-CDR loop.

Maturation of shark single-domain (IgNAR) antibodies: evidence for induced-fit binding.,Stanfield RL, Dooley H, Verdino P, Flajnik MF, Wilson IA J Mol Biol. 2007 Mar 23;367(2):358-72. Epub 2006 Dec 22. PMID:17258766<ref>PMID:17258766</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2i27" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Ginci]]
[[Category: Large Structures]]
[[Category: Stanfield, R L]]
[[Category: Wilson, I A]]
[[Category: Immune system]]
[[Category: Immunoglobulin fold]]