View source for 6iwg


==Crystal structure of rhesus macaque MHC class I molecule Mamu-B*05104 complexed with N-myristoylated 4-mer lipopeptide derived from SIV nef protein==
<StructureSection load='6iwg' size='340' side='right'caption='[[6iwg]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6iwg]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Macaca_mulatta Macaca mulatta] and [https://en.wikipedia.org/wiki/Simian_immunodeficiency_virus Simian immunodeficiency virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6IWG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6IWG 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BO3:BORIC+ACID'>BO3</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MYR:MYRISTIC+ACID'>MYR</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=6iwg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6iwg OCA], [https://pdbe.org/6iwg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6iwg RCSB], [https://www.ebi.ac.uk/pdbsum/6iwg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6iwg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B2ZHY7_MACMU B2ZHY7_MACMU] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Similar to host proteins, N-myristoylation occurs for viral proteins to dictate their pathological function. However, this lipid-modifying reaction creates a novel class of "lipopeptide" Ags targeted by host CTLs. The primate MHC class I-encoded protein, Mamu-B*098, was previously shown to bind N-myristoylated 5-mer peptides. Nevertheless, T cells exist that recognize even shorter lipopeptides, and much remains to be elucidated concerning the molecular mechanisms of lipopeptide presentation. We, in this study, demonstrate that the MHC class I allele, Mamu-B*05104, binds the N-myristoylated 4-mer peptide (C14-Gly-Gly-Ala-Ile) derived from the viral Nef protein for its presentation to CTLs. A phylogenetic tree analysis indicates that these classical MHC class I alleles are not closely associated; however, the high-resolution x-ray crystallographic analyses indicate that both molecules share lipid-binding structures defined by the exceptionally large, hydrophobic B pocket to accommodate the acylated glycine (G1) as an anchor. The C-terminal isoleucine (I4) of C14-Gly-Gly-Ala-Ile anchors at the F pocket, which is distinct from that of Mamu-B*098 and is virtually identical to that of the peptide-presenting MHC class I molecule, HLA-B51. The two central amino acid residues (G2 and A3) are only exposed externally for recognition by T cells, and the methyl side chain on A3 constitutes a major T cell epitope, underscoring that the epitopic diversity is highly limited for lipopeptides as compared with that for MHC class I-presented long peptides. These structural features suggest that lipopeptide-presenting MHC class I alleles comprise a distinct MHC class I subset that mediates an alternative pathway for CTL activation.

Identification and Structure of an MHC Class I-Encoded Protein with the Potential to Present N-Myristoylated 4-mer Peptides to T Cells.,Yamamoto Y, Morita D, Shima Y, Midorikawa A, Mizutani T, Suzuki J, Mori N, Shiina T, Inoko H, Tanaka Y, Mikami B, Sugita M J Immunol. 2019 Jun 15;202(12):3349-3358. doi: 10.4049/jimmunol.1900087. Epub, 2019 May 1. PMID:31043477<ref>PMID:31043477</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6iwg" 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/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Macaca mulatta]]
[[Category: Simian immunodeficiency virus]]
[[Category: Morita D]]
[[Category: Sugita M]]
[[Category: Yamamoto Y]]