View source for 6pvd


==Structure of human MAIT A-F7 TCR in complex with human MR1-NV18.1==
<StructureSection load='6pvd' size='340' side='right'caption='[[6pvd]], [[Resolution|resolution]] 2.14&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6pvd]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6PVD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PVD 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]] 2.14&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=N18:methyl+3-[[2,4-bis(oxidanylidene)-1~{H}-pyrimidin-6-yl]carbonylamino]propanoate'>N18</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=6pvd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pvd OCA], [https://pdbe.org/6pvd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6pvd RCSB], [https://www.ebi.ac.uk/pdbsum/6pvd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6pvd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HMR1_HUMAN HMR1_HUMAN] Has antigen presentation function. Involved in the development and expansion of a small population of T-cells expressing an invariant T-cell receptor alpha chain called mucosal-associated invariant T-cells (MAIT). MAIT cells are preferentially located in the gut lamina propria and therefore may be involved in monitoring commensal flora or serve as a distress signal. Expression and MAIT cell recognition seem to be ligand-dependent.<ref>PMID:12794138</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The antigen-presenting molecule MR1 presents riboflavin-based metabolites to Mucosal-Associated Invariant T (MAIT) cells. While MR1 egress to the cell surface is ligand-dependent, the ability of small-molecule ligands to impact on MR1 cellular trafficking remains unknown. Arising from an in silico screen of the MR1 ligand-binding pocket, we identify one ligand, 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoic acid, DB28, as well as an analog, methyl 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoate, NV18.1, that down-regulate MR1 from the cell surface and retain MR1 molecules in the endoplasmic reticulum (ER) in an immature form. DB28 and NV18.1 compete with the known MR1 ligands, 5-OP-RU and acetyl-6-FP, for MR1 binding and inhibit MR1-dependent MAIT cell activation. Crystal structures of the MAIT T cell receptor (TCR) complexed with MR1-DB28 and MR1-NV18.1, show that these two ligands reside within the A'-pocket of MR1. Neither ligand forms a Schiff base with MR1 molecules; both are nevertheless sequestered by a network of hydrophobic and polar contacts. Accordingly, we define a class of compounds that inhibits MR1 cellular trafficking.

Ligand-dependent downregulation of MR1 cell surface expression.,Salio M, Awad W, Veerapen N, Gonzalez-Lopez C, Kulicke C, Waithe D, Martens AWJ, Lewinsohn DM, Hobrath JV, Cox LR, Rossjohn J, Besra GS, Cerundolo V Proc Natl Acad Sci U S A. 2020 Apr 27. pii: 2003136117. doi:, 10.1073/pnas.2003136117. PMID:32341160<ref>PMID:32341160</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6pvd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-2 microglobulin 3D structures|Beta-2 microglobulin 3D structures]]
*[[MHC 3D structures|MHC 3D structures]]
*[[MHC I 3D structures|MHC I 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Awad W]]
[[Category: Rossjohn J]]