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{{STRUCTURE_1klu|  PDB=1klu  |  SCENE=  }}
===Crystal structure of HLA-DR1/TPI(23-37) complexed with staphylococcal enterotoxin C3 variant 3B2 (SEC3-3B2)===
{{ABSTRACT_PUBMED_12051920}}


==Disease==
==Crystal structure of HLA-DR1/TPI(23-37) complexed with staphylococcal enterotoxin C3 variant 3B2 (SEC3-3B2)==
[[http://www.uniprot.org/uniprot/2B11_HUMAN 2B11_HUMAN]] Genetic variation in HLA-DRB1 is a cause of susceptibility to sarcoidosis type 1 (SS1) [MIM:[http://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>
<StructureSection load='1klu' size='340' side='right'caption='[[1klu]], [[Resolution|resolution]] 1.93&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1klu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] 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=1KLU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KLU 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]] 1.93&#8491;</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=1klu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1klu OCA], [https://pdbe.org/1klu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1klu RCSB], [https://www.ebi.ac.uk/pdbsum/1klu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1klu ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/TPIS_HUMAN TPIS_HUMAN] Defects in TPI1 are the cause of triosephosphate isomerase deficiency (TPI deficiency) [MIM:[https://omim.org/entry/190450 190450]. TPI deficiency is an autosomal recessive disorder. It is the most severe clinical disorder of glycolysis. It is associated with neonatal jaundice, chronic hemolytic anemia, progressive neuromuscular dysfunction, cardiomyopathy and increased susceptibility to infection.
== Function ==
[https://www.uniprot.org/uniprot/TPIS_HUMAN TPIS_HUMAN]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/kl/1klu_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1klu ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
While most immunotherapies for cancer have focused on eliciting specific CD8+ cytotoxic T lymphocyte killing of tumor cells, a mounting body of evidence suggests that stimulation of anti-tumor CD4+ T cell help may be required for highly effective therapy. Several MHC class II-restricted tumor antigens that specifically activate such CD4+ helper T lymphocytes have now been identified, including one from a melanoma tumor that is caused by a single base-pair mutation in the glycolytic enzyme triosephosphate isomerase. This mutation results in the conversion of a threonine residue to isoleucine within the antigenic epitope, concomitant with a greater than five log-fold increase in stimulation of a CD4+ tumor-infiltrating lymphocyte line. Here, we present the crystal structures of HLA-DR1 in complex with both wild-type and mutant TPI peptide antigens, the first structures of tumor peptide antigen/MHC class II complexes recognized by CD4+ T cells to be reported. These structures show that very minor changes in the binding surface for T cell receptor correspond to the dramatic differences in T cell stimulation. Defining the structural basis by which CD4+ T cell help is invoked in an anti-tumor immune response will likely aid the design of more effective cancer immunotherapies.


==Function==
Minor structural changes in a mutated human melanoma antigen correspond to dramatically enhanced stimulation of a CD4+ tumor-infiltrating lymphocyte line.,Sundberg EJ, Sawicki MW, Southwood S, Andersen PS, Sette A, Mariuzza RA J Mol Biol. 2002 May 31;319(2):449-61. PMID:12051920<ref>PMID:12051920</ref>
[[http://www.uniprot.org/uniprot/ENTC3_STAAU ENTC3_STAAU]] Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness is characterized by high fever, hypotension, diarrhea, shock, and in some cases death. [[http://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. [[http://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.


==About this Structure==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
[[1klu]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KLU OCA].
</div>
<div class="pdbe-citations 1klu" style="background-color:#fffaf0;"></div>


==See Also==
==See Also==
*[[Major histocompatibility complex|Major histocompatibility complex]]
*[[MHC 3D structures|MHC 3D structures]]
 
*[[MHC II 3D structures|MHC II 3D structures]]
==Reference==
== References ==
<ref group="xtra">PMID:012051920</ref><references group="xtra"/><references/>
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Staphylococcus aureus]]
[[Category: Staphylococcus aureus]]
[[Category: Andersen, P S.]]
[[Category: Andersen PS]]
[[Category: Mariuzza, R A.]]
[[Category: Mariuzza RA]]
[[Category: Sawicki, M W.]]
[[Category: Sawicki MW]]
[[Category: Sette, A.]]
[[Category: Sette A]]
[[Category: Sidney, J.]]
[[Category: Sidney J]]
[[Category: Sundberg, E J.]]
[[Category: Sundberg EJ]]
[[Category: Cd4+ t cell]]
[[Category: Enterotoxin c3]]
[[Category: Hla-dr1/tpi]]
[[Category: Human melanoma antigen]]
[[Category: Immune system-toxin complex]]

Latest revision as of 09:54, 30 October 2024

Crystal structure of HLA-DR1/TPI(23-37) complexed with staphylococcal enterotoxin C3 variant 3B2 (SEC3-3B2)Crystal structure of HLA-DR1/TPI(23-37) complexed with staphylococcal enterotoxin C3 variant 3B2 (SEC3-3B2)

Structural highlights

1klu is a 4 chain structure with sequence from Homo sapiens and Staphylococcus aureus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.93Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

TPIS_HUMAN Defects in TPI1 are the cause of triosephosphate isomerase deficiency (TPI deficiency) [MIM:190450. TPI deficiency is an autosomal recessive disorder. It is the most severe clinical disorder of glycolysis. It is associated with neonatal jaundice, chronic hemolytic anemia, progressive neuromuscular dysfunction, cardiomyopathy and increased susceptibility to infection.

Function

TPIS_HUMAN

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

While most immunotherapies for cancer have focused on eliciting specific CD8+ cytotoxic T lymphocyte killing of tumor cells, a mounting body of evidence suggests that stimulation of anti-tumor CD4+ T cell help may be required for highly effective therapy. Several MHC class II-restricted tumor antigens that specifically activate such CD4+ helper T lymphocytes have now been identified, including one from a melanoma tumor that is caused by a single base-pair mutation in the glycolytic enzyme triosephosphate isomerase. This mutation results in the conversion of a threonine residue to isoleucine within the antigenic epitope, concomitant with a greater than five log-fold increase in stimulation of a CD4+ tumor-infiltrating lymphocyte line. Here, we present the crystal structures of HLA-DR1 in complex with both wild-type and mutant TPI peptide antigens, the first structures of tumor peptide antigen/MHC class II complexes recognized by CD4+ T cells to be reported. These structures show that very minor changes in the binding surface for T cell receptor correspond to the dramatic differences in T cell stimulation. Defining the structural basis by which CD4+ T cell help is invoked in an anti-tumor immune response will likely aid the design of more effective cancer immunotherapies.

Minor structural changes in a mutated human melanoma antigen correspond to dramatically enhanced stimulation of a CD4+ tumor-infiltrating lymphocyte line.,Sundberg EJ, Sawicki MW, Southwood S, Andersen PS, Sette A, Mariuzza RA J Mol Biol. 2002 May 31;319(2):449-61. PMID:12051920[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Sundberg EJ, Sawicki MW, Southwood S, Andersen PS, Sette A, Mariuzza RA. Minor structural changes in a mutated human melanoma antigen correspond to dramatically enhanced stimulation of a CD4+ tumor-infiltrating lymphocyte line. J Mol Biol. 2002 May 31;319(2):449-61. PMID:12051920 doi:http://dx.doi.org/10.1016/S0022-2836(02)00370-4

1klu, resolution 1.93Å

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