View source for 2kqy


==Solution structure of Avian Thymic Hormone==
<StructureSection load='2kqy' size='340' side='right'caption='[[2kqy]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2kqy]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2KQY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2KQY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=2kqy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2kqy OCA], [https://pdbe.org/2kqy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2kqy RCSB], [https://www.ebi.ac.uk/pdbsum/2kqy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2kqy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PRVT_CHICK PRVT_CHICK] Appears to promote immune maturation in bone marrow cells in culture. Binds two calcium ions.
== 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/kq/2kqy_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=2kqy ConSurf].
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== Publication Abstract from PubMed ==
Originally isolated on the basis of its capacity to stimulate T-cell maturation and proliferation, avian thymic hormone (ATH) is nevertheless a parvalbumin, one of two beta-lineage isoforms expressed in birds. We recently learned that addition of Ca(2+)-free ATH to a solution of 8-anilinonaphthalene-1-sulfonate (ANS) markedly increases ANS emission. This behavior, not observed in the presence of Ca(2+), suggests that apolar surface area buried in the Ca(2+)-bound state becomes solvent accessible upon Ca(2+) removal. In order to elucidate the conformational alterations that accompany Ca(2+) binding, we have obtained the solution structure of the Ca(2+)-free protein using NMR spectroscopy and compared it to the Ca(2+)-loaded protein, solved by X-ray crystallography. Although the metal-ion-binding (CD-EF) domains are largely coincident in the superimposed structures, a major difference is observed in the AB domains. The tight association of helix B with the E and F helices in the Ca(2+)-bound state is lost upon removal of Ca(2+), producing a deep hydrophobic cavity. The B helix also undergoes substantial rotation, exposing the side chains of F24, Y26, F29, and F30 to solvent. Presumably, the increase in ANS emission observed in the presence of unliganded ATH reflects the interaction of these hydrophobic residues with the fluorescent probe. The increased solvent exposure of apolar surface area in the Ca(2+)-free protein is consistent with previously collected scanning calorimetry data, which indicated an unusually low change in heat capacity upon thermal denaturation. The Ca(2+)-free structure also provides added insight into the magnitude of ligation-linked conformational alteration compatible with a high-affinity metal-ion-binding signature. The exposure of substantial apolar surface area suggests the intriguing possibility that ATH could function as a reverse Ca(2+) sensor.

Structure of avian thymic hormone, a high-affinity avian beta-parvalbumin, in the Ca2+-free and Ca2+-bound states.,Schuermann JP, Tan A, Tanner JJ, Henzl MT J Mol Biol. 2010 Apr 9;397(4):991-1002. Epub 2010 Feb 12. PMID:20156445<ref>PMID:20156445</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Parvalbumin|Parvalbumin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gallus gallus]]
[[Category: Large Structures]]
[[Category: Henzl MT]]