View source for 2axg

==The Immunogenicity of a Viral Cytotoxic T Cell Epitope is controlled by its MHC-bound Conformation==
<StructureSection load='2axg' size='340' side='right' caption='[[2axg]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2axg]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AXG OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2AXG FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACY:ACETIC+ACID'>ACY</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2axf|2axf]]</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2axg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2axg OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2axg RCSB], [http://www.ebi.ac.uk/pdbsum/2axg PDBsum]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:[http://omim.org/entry/241600 241600]]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.<ref>PMID:16549777</ref>   Note=Beta-2-microglobulin may adopt the fibrillar configuration of amyloid in certain pathologic states. The capacity to assemble into amyloid fibrils is concentration dependent. Persistently high beta(2)-microglobulin serum levels lead to amyloidosis in patients on long-term hemodialysis.<ref>PMID:3532124</ref> <ref>PMID:1336137</ref> <ref>PMID:7554280</ref> <ref>PMID:4586824</ref> <ref>PMID:8084451</ref> <ref>PMID:12119416</ref> <ref>PMID:12796775</ref> <ref>PMID:16901902</ref> <ref>PMID:16491088</ref> <ref>PMID:17646174</ref> <ref>PMID:18835253</ref> <ref>PMID:18395224</ref> <ref>PMID:19284997</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/1B35_HUMAN 1B35_HUMAN]] Involved in the presentation of foreign antigens to the immune system. [[http://www.uniprot.org/uniprot/BZLF1_EBV BZLF1_EBV]] Plays a key role in the switch from latent infection to lytic cycle producing new virions. Acts as a transcription factor, inducing early lytic cycle genes, and as a origin binding protein for genome replication. BZLF1 activates the promoter of another EBV gene (BSLF2+BMLF1).<ref>PMID:2157874</ref> <ref>PMID:1847997</ref> <ref>PMID:8404860</ref> <ref>PMID:17079287</ref> <ref>PMID:19144704</ref>  [[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN]] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. 
== 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/ax/2axg_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Thousands of potentially antigenic peptides are encoded by an infecting pathogen; however, only a small proportion induce measurable CD8(+) T cell responses. To investigate the factors that control peptide immunogenicity, we have examined the cytotoxic T lymphocyte (CTL) response to a previously undefined epitope ((77)APQPAPENAY(86)) from the BZLF1 protein of Epstein-Barr virus (EBV). This peptide binds well to two human histocompatibility leukocyte antigen (HLA) allotypes, HLA-B*3501 and HLA-B*3508, which differ by a single amino acid at position 156 ((156)Leucine vs. (156)Arginine, respectively). Surprisingly, only individuals expressing HLA-B*3508 show evidence of a CTL response to the (77)APQPAPENAY(86) epitope even though EBV-infected cells expressing HLA-B*3501 process and present similar amounts of peptide for CTL recognition, suggesting that factors other than peptide presentation levels are influencing immunogenicity. Functional and structural analysis revealed marked conformational differences in the peptide, when bound to each HLA-B35 allotype, that are dictated by the polymorphic HLA residue 156 and that directly affected T cell receptor recognition. These data indicate that the immunogenicity of an antigenic peptide is influenced not only by how well the peptide binds to major histocompatibility complex (MHC) molecules but also by its bound conformation. It also illustrates a novel mechanism through which MHC polymorphism can further diversify the immune response to infecting pathogens.

The immunogenicity of a viral cytotoxic T cell epitope is controlled by its MHC-bound conformation.,Tynan FE, Elhassen D, Purcell AW, Burrows JM, Borg NA, Miles JJ, Williamson NA, Green KJ, Tellam J, Kjer-Nielsen L, McCluskey J, Rossjohn J, Burrows SR J Exp Med. 2005 Nov 7;202(9):1249-60. PMID:16275762<ref>PMID:16275762</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Beta-2 microglobulin|Beta-2 microglobulin]]
*[[Major histocompatibility complex|Major histocompatibility complex]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Borg, N A]]
[[Category: Burrows, J M]]
[[Category: Burrows, S R]]
[[Category: Elhassen, D]]
[[Category: Green, K J]]
[[Category: Kjer-Nielsen, L]]
[[Category: McCluskey, J]]
[[Category: Miles, J J]]
[[Category: Purcell, A W]]
[[Category: Rossjohn, J]]
[[Category: Tellam, J]]
[[Category: Tynan, F E]]
[[Category: Williamson, N A]]
[[Category: Immune response]]
[[Category: Immune system-gene regulation complex]]
[[Category: Pmhc]]