View source for 2q86


==Structure of the mouse invariant NKT cell receptor Valpha14==
<StructureSection load='2q86' size='340' side='right'caption='[[2q86]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2q86]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2Q86 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2Q86 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=FUC:ALPHA-L-FUCOSE'>FUC</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></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=2q86 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2q86 OCA], [https://pdbe.org/2q86 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2q86 RCSB], [https://www.ebi.ac.uk/pdbsum/2q86 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2q86 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRAC_MOUSE TRAC_MOUSE] Constant region of T cell receptor (TR) alpha chain. Alpha-beta T cell receptors are antigen specific receptors which are essential to the immune response and are present on the cell surface of T lymphocytes. Recognize peptide-major histocompatibility (MH) (pMH) complexes that are displayed by antigen presenting cells (APC), a prerequisite for efficient T cell adaptive immunity against pathogens. Binding of alpha-beta TR to pMH complex initiates TR-CD3 clustering on the cell surface and intracellular activation of LCK that phosphorylates the ITAM motifs of CD3G, CD3D, CD3E and CD247 enabling the recruitment of ZAP70. In turn, ZAP70 phosphorylates LAT, which recruits numerous signaling molecules to form the LAT signalosome. The LAT signalosome propagates signal branching to three major signaling pathways, the calcium, the mitogen-activated protein kinase (MAPK) kinase and the nuclear factor NF-kappa-B (NF-kB) pathways, leading to the mobilization of transcription factors that are critical for gene expression and essential for T cell growth and differentiation. The T cell repertoire is generated in the thymus, by V-(D)-J rearrangement. This repertoire is then shaped by intrathymic selection events to generate a peripheral T cell pool of self-MH restricted, non-autoaggressive T cells. Post-thymic interaction of alpha-beta TR with the pMH complexes shapes TR structural and functional avidity.[UniProtKB:P01848]
== 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/q8/2q86_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2q86 ConSurf].
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== Publication Abstract from PubMed ==
The semi-invariant Valpha14Jalpha18 T cell receptor (TCR) is expressed by regulatory NKT cells and has the unique ability to recognize chemically diverse ligands presented by CD1d. The crystal structure of CD1d complexed to a natural, endogenous ligand, isoglobotrihexosylceramide (iGb3), illustrates the extent of this diversity when compared to the binding of potent, exogenous ligands, such as alpha-galactosylceramide (alpha-GalCer). A single mode of recognition for these two classes of ligands would then appear problematic for a single T cell receptor. However, the Valpha14 TCR adopts two different conformations in the crystal where, in one configuration, the presence of a larger cavity between the two CDR3 regions could accommodate iGb3 and, in the other, a smaller cavity fits alpha-GalCer more snugly. Alternatively, the extended iGb3 headgroup could be "squashed" upon docking of the TCR and accommodated between the CD1 and TCR surfaces. Thus, the same TCR may adopt alternative modes of recognition for these foreign and self-ligands for NKT cell activation.

Crystal structures of mouse CD1d-iGb3 complex and its cognate Valpha14 T cell receptor suggest a model for dual recognition of foreign and self glycolipids.,Zajonc DM, Savage PB, Bendelac A, Wilson IA, Teyton L J Mol Biol. 2008 Apr 4;377(4):1104-16. Epub 2008 Jan 31. PMID:18295796<ref>PMID:18295796</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 2q86" style="background-color:#fffaf0;"></div>

==See Also==
*[[T-cell receptor 3D structures|T-cell receptor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Zajonc DM]]