View source for 7lfk


==MODEL OF MHC CLASS Ib H2-M3 WITH MOUSE ND1 N-TERMINAL HEPTAPEPTIDE, THR MUTANT, REFINED AT 1.60 ANGSTROMS RESOLUTION==
<StructureSection load='7lfk' size='340' side='right'caption='[[7lfk]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7lfk]] is a 6 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=7LFK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7LFK 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]] 1.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FME:N-FORMYLMETHIONINE'>FME</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=7lfk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7lfk OCA], [https://pdbe.org/7lfk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7lfk RCSB], [https://www.ebi.ac.uk/pdbsum/7lfk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7lfk ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Presentation of antigenic peptides to T-cell receptors is an essential step in the adaptive immune response. In the mouse the class Ib major histocompatibility complex molecule, H2-M3, presents bacterial- and mitochondrial-derived peptides to T-cell receptors on cytotoxic T cells. Four mitochondrial heptapeptides, differing only at residue 6, form complexes with H2-M3 which can be distinguished by T cells. No structures of relevant receptors are available. To investigate the structural basis for this distinction, crystal structures were determined and molecular dynamics simulations over one microsecond were done for each complex. In the crystal structures of the heptapeptide complexes with H2-M3, presented here, the side chains of the peptide residues at position 6 all point into the H2-M3 binding groove, and are thus inaccessible, so that the very similar structures do not suggest how recognition and initiation of responses by the T cells may occur. However, conformational differences, which could be crucial to T-cell discrimination, appear within one microsecond during molecular dynamics simulations of the four complexes. Specifically, the three C-terminal residues of peptide ligands with alanine or threonine at position 6 partially exit the binding groove; this does not occur in peptide ligands with isoleucine or valine at position 6. Structural changes associated with partial peptide exit from the binding groove, along with relevant peptide binding energetics and immunological results are discussed. Communicated by Ramaswamy H. Sarma.

Structure and dynamics of major histocompatibility class Ib molecule H2-M3 complexed with mitochondrial-derived peptides.,Strand A, Shen ST, Tomchick DR, Wang J, Wang CR, Deisenhofer J J Biomol Struct Dyn. 2022;40(20):10300-10312. doi: 10.1080/07391102.2021.1942214. , Epub 2021 Jun 28. PMID:34176438<ref>PMID:34176438</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7lfk" 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: Mus musculus]]
[[Category: Deisenhofer J]]
[[Category: Shen S]]
[[Category: Tomchick DR]]