View source for 4iiq


==Crystal structure of a human MAIT TCR in complex with bovine MR1==
<StructureSection load='4iiq' size='340' side='right'caption='[[4iiq]], [[Resolution|resolution]] 2.86&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4iiq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus] and [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IIQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4IIQ FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=KFP:N~6~-[(2-AMINO-4-OXO-3,4-DIHYDROPTERIDIN-6-YL)METHYL]-D-LYSINE'>KFP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4iiq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4iiq OCA], [https://pdbe.org/4iiq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4iiq RCSB], [https://www.ebi.ac.uk/pdbsum/4iiq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4iiq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q6P4G7_HUMAN Q6P4G7_HUMAN] 
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== Publication Abstract from PubMed ==
Mucosal-associated invariant T (MAIT) cells are an evolutionarily conserved alphabeta T-cell lineage that express a semi-invariant T-cell receptor (TCR) restricted to the MHC related-1 (MR1) protein. MAIT cells are dependent upon MR1 expression and exposure to microbes for their development and stimulation, yet these cells can exhibit microbial-independent stimulation when responding to MR1 from different species. We have used this microbial-independent, cross-species reactivity of MAIT cells to define the molecular basis of MAIT-TCR/MR1 engagement and present here a 2.85 A complex structure of a human MAIT-TCR bound to bovine MR1. The MR1 binding groove is similar in backbone structure to classical peptide-presenting MHC class I molecules (MHCp), yet is partially occluded by large aromatic residues that form cavities suitable for small ligand presentation. The docking of the MAIT-TCR on MR1 is perpendicular to the MR1 surface and straddles the MR1 alpha1 and alpha2 helices, similar to classical alphabeta TCR engagement of MHCp. However, the MAIT-TCR contacts are dominated by the alpha-chain, focused on the MR1 alpha2 helix. TCR beta-chain contacts are mostly through the variable CDR3beta loop that is positioned proximal to the CDR3alpha loop directly over the MR1 open groove. The elucidation of the MAIT TCR/MR1 complex structure explains how the semi-invariant MAIT-TCR engages the nonpolymorphic MR1 protein, and sheds light onto ligand discrimination by this cell type. Importantly, this structure also provides a critical link in our understanding of the evolution of alphabeta T-cell recognition of MHC and MHC-like ligands.

The molecular basis for Mucosal-Associated Invariant T cell recognition of MR1 proteins.,Lopez-Sagaseta J, Dulberger CL, Crooks JE, Parks CD, Luoma AM, McFedries A, Van Rhijn I, Saghatelian A, Adams EJ Proc Natl Acad Sci U S A. 2013 May 7;110(19):E1771-8. doi:, 10.1073/pnas.1222678110. Epub 2013 Apr 23. PMID:23613577<ref>PMID:23613577</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4iiq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-2 microglobulin 3D structures|Beta-2 microglobulin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Bos taurus]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Adams EJ]]
[[Category: Lopez-Sagaseta J]]