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| | <StructureSection load='2xn9' size='340' side='right'caption='[[2xn9]], [[Resolution|resolution]] 2.30Å' scene=''> | | <StructureSection load='2xn9' size='340' side='right'caption='[[2xn9]], [[Resolution|resolution]] 2.30Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2xn9]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/"micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885] and [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XN9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XN9 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2xn9]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens], [https://en.wikipedia.org/wiki/Influenza_A_virus Influenza A virus] and [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XN9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XN9 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.3Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1d6e|1d6e]], [[1enf|1enf]], [[2esv|2esv]], [[1seb|1seb]], [[1jws|1jws]], [[1h15|1h15]], [[1f77|1f77]], [[2seb|2seb]], [[2ak4|2ak4]], [[2gj6|2gj6]], [[2wbj|2wbj]], [[1klu|1klu]], [[1fyt|1fyt]], [[1pyw|1pyw]], [[1j8h|1j8h]], [[1klg|1klg]], [[2g9h|2g9h]], [[1ktk|1ktk]], [[1dlh|1dlh]], [[2bnq|2bnq]], [[1d5z|1d5z]], [[2eyr|2eyr]], [[1t5x|1t5x]], [[1a6a|1a6a]], [[1kg0|1kg0]], [[1bx2|1bx2]], [[1d5m|1d5m]], [[1lo5|1lo5]], [[1hxy|1hxy]], [[1hqr|1hqr]], [[1qrn|1qrn]], [[2bnr|2bnr]], [[1kgc|1kgc]], [[2cdg|2cdg]], [[1fv1|1fv1]], [[1sjh|1sjh]], [[2eys|2eys]], [[2bnu|2bnu]], [[1jwm|1jwm]], [[2cdf|2cdf]], [[1mi5|1mi5]], [[1ymm|1ymm]], [[1r5i|1r5i]], [[1zgl|1zgl]], [[1ewc|1ewc]], [[1t5w|1t5w]], [[1d5x|1d5x]], [[2axh|2axh]], [[1aqd|1aqd]], [[2eyt|2eyt]], [[1sje|1sje]], [[1oga|1oga]], [[1jwu|1jwu]], [[2cde|2cde]], [[2xna|2xna]]</div></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=2xn9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xn9 OCA], [https://pdbe.org/2xn9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xn9 RCSB], [https://www.ebi.ac.uk/pdbsum/2xn9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xn9 ProSAT]</span></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=2xn9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xn9 OCA], [https://pdbe.org/2xn9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xn9 RCSB], [https://www.ebi.ac.uk/pdbsum/2xn9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xn9 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Disease == | | == Disease == |
| - | [[https://www.uniprot.org/uniprot/2B11_HUMAN 2B11_HUMAN]] Genetic variation in HLA-DRB1 is a cause of susceptibility to sarcoidosis type 1 (SS1) [MIM:[https://omim.org/entry/181000 181000]]. Sarcoidosis is an idiopathic, systemic, inflammatory disease characterized by the formation of immune granulomas in involved organs. Granulomas predominantly invade the lungs and the lymphatic system, but also skin, liver, spleen, eyes and other organs may be involved.<ref>PMID:14508706</ref>
| + | [https://www.uniprot.org/uniprot/TRAC_HUMAN TRAC_HUMAN] TCR-alpha-beta-positive T-cell deficiency. The disease is caused by variants affecting the gene represented in this entry. |
| | == Function == | | == Function == |
| - | [[https://www.uniprot.org/uniprot/A8CDU0_9INFA A8CDU0_9INFA]] Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization of about two third of the virus particles through clathrin-dependent endocytosis and about one third through a clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore.[RuleBase:RU003324][SAAS:SAAS00145386] [[https://www.uniprot.org/uniprot/ETXH_STAAU ETXH_STAAU]] Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness characterized by high fever, hypotension, diarrhea, shock, and in some cases death. [[https://www.uniprot.org/uniprot/DRA_HUMAN DRA_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading. [[https://www.uniprot.org/uniprot/2B11_HUMAN 2B11_HUMAN]] Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route; where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules; and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments; exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides; autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs; other cells of the gastrointestinal tract; such as epithelial cells; express MHC class II molecules and CD74 and act as APCs; which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen; three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs; CD74 undergoes a sequential degradation by various proteases; including CTSS and CTSL; leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells; the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal miroenvironment has been implicated in the regulation of antigen loading into MHC II molecules; increased acidification produces increased proteolysis and efficient peptide loading.
| + | [https://www.uniprot.org/uniprot/TRAC_HUMAN TRAC_HUMAN] Constant region of T cell receptor (TR) alpha chain (PubMed:24600447). 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 (PubMed:25493333). 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 (PubMed:23524462). 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 (PubMed:15040585).<ref>PMID:15040585</ref> <ref>PMID:23524462</ref> <ref>PMID:24600447</ref> <ref>PMID:25493333</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | ==See Also== | | ==See Also== |
| | *[[MHC 3D structures|MHC 3D structures]] | | *[[MHC 3D structures|MHC 3D structures]] |
| | + | *[[MHC II 3D structures|MHC II 3D structures]] |
| | *[[T-cell receptor 3D structures|T-cell receptor 3D structures]] | | *[[T-cell receptor 3D structures|T-cell receptor 3D structures]] |
| | == References == | | == References == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Human]] | + | [[Category: Homo sapiens]] |
| | + | [[Category: Influenza A virus]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Fischer, G]] | + | [[Category: Staphylococcus aureus]] |
| - | [[Category: Karlsson, B G]] | + | [[Category: Fischer G]] |
| - | [[Category: Lindkvist-Petersson, K]] | + | [[Category: Karlsson BG]] |
| - | [[Category: Orekhov, V Y]] | + | [[Category: Lindkvist-Petersson K]] |
| - | [[Category: Rodstrom, K E.J]] | + | [[Category: Orekhov VY]] |
| - | [[Category: Saline, M]] | + | [[Category: Rodstrom KEJ]] |
| - | [[Category: Immune system]]
| + | [[Category: Saline M]] |
| - | [[Category: Immunoreceptor]]
| + | |
| - | [[Category: Superantigen]]
| + | |
| - | [[Category: Ternary complex]]
| + | |
| Structural highlights
Disease
TRAC_HUMAN TCR-alpha-beta-positive T-cell deficiency. The disease is caused by variants affecting the gene represented in this entry.
Function
TRAC_HUMAN Constant region of T cell receptor (TR) alpha chain (PubMed:24600447). 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 (PubMed:25493333). 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 (PubMed:23524462). 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 (PubMed:15040585).[1] [2] [3] [4]
Publication Abstract from PubMed
Superantigens (SAgs) are bacterial toxins that interact with immunoreceptors, T cell receptor (TCR) and major histocompatibility complex (MHC) class II, conventionally through the variable beta-domain of TCR (TCRVbeta). They induce a massive release of cytokines, which can lead to diseases such as food poisoning and toxic shock syndrome. In this study, we report the X-ray structure of the ternary complex between staphylococcal enterotoxin H (SEH) and its human receptors, MHC class II and TCR. The structure demonstrates that SEH predominantly interacts with the variable alpha-domain of TCR (TCRValpha), which is supported by nuclear magnetic resonance (NMR) analyses. Furthermore, there is no contact between MHC and TCR upon complex formation. Structural analyses suggest that the major contact points to TCRValpha are conserved among other bacterial SAgs. Consequently, a new dimension of SAg biology emerges, suggesting that in addition to the conventional interactions with the TCRVbeta domain, SAgs can also activate T cells through the TCRValpha domain.
The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation.,Saline M, Rodstrom KE, Fischer G, Orekhov VY, Karlsson BG, Lindkvist-Petersson K Nat Commun. 2010 Nov 16;1:119. PMID:21081917[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Nikolich-Zugich J, Slifka MK, Messaoudi I. The many important facets of T-cell repertoire diversity. Nat Rev Immunol. 2004 Feb;4(2):123-32. doi: 10.1038/nri1292. PMID:15040585 doi:http://dx.doi.org/10.1038/nri1292
- ↑ Brownlie RJ, Zamoyska R. T cell receptor signalling networks: branched, diversified and bounded. Nat Rev Immunol. 2013 Apr;13(4):257-69. doi: 10.1038/nri3403. PMID:23524462 doi:http://dx.doi.org/10.1038/nri3403
- ↑ Lefranc MP. Immunoglobulin and T Cell Receptor Genes: IMGT((R)) and the Birth and Rise of Immunoinformatics. Front Immunol. 2014 Feb 5;5:22. doi: 10.3389/fimmu.2014.00022. eCollection 2014. PMID:24600447 doi:http://dx.doi.org/10.3389/fimmu.2014.00022
- ↑ Rossjohn J, Gras S, Miles JJ, Turner SJ, Godfrey DI, McCluskey J. T cell antigen receptor recognition of antigen-presenting molecules. Annu Rev Immunol. 2015;33:169-200. doi: 10.1146/annurev-immunol-032414-112334., Epub 2014 Dec 10. PMID:25493333 doi:http://dx.doi.org/10.1146/annurev-immunol-032414-112334
- ↑ Saline M, Rodstrom KE, Fischer G, Orekhov VY, Karlsson BG, Lindkvist-Petersson K. The structure of superantigen complexed with TCR and MHC reveals novel insights into superantigenic T cell activation. Nat Commun. 2010 Nov 16;1:119. PMID:21081917 doi:10.1038/ncomms1117
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