1kpr: Difference between revisions
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==The human non-classical major histocompatibility complex molecule HLA-E== | |||
<StructureSection load='1kpr' size='340' side='right' caption='[[1kpr]], [[Resolution|resolution]] 2.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1kpr]] is a 6 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=1KPR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1KPR FirstGlance]. <br> | |||
==Disease== | </td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br> | ||
[[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> | <tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1mhe|1mhe]], [[1ktl|1ktl]]</td></tr> | ||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HLA-E ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]), B2M ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1kpr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kpr OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1kpr RCSB], [http://www.ebi.ac.uk/pdbsum/1kpr 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/HLAE_HUMAN HLAE_HUMAN]] Preferably binds to a peptide derived from the signal sequence of most HLA-A, -B, -C and -G molecules. [[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/kp/1kpr_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 == | |||
Previous studies of HLA-E allelic polymorphism have indicated that balancing selection may be acting to maintain two major alleles in most populations, indicating that a functional difference may exist between the alleles. The alleles differ at only one amino acid position, where an arginine at position 107 in HLA-E*0101 (E(R)) is replaced by a glycine in HLA-E*0103 (E(G)). To investigate possible functional differences, we have undertaken a study of the physical and biochemical properties of these two proteins. By comparing expression levels, we found that whereas steady-state protein levels were similar, the two alleles did in fact differ with respect to cell surface levels. To help explain this difference, we undertook studies of the relative differences in peptide affinity, complex stability, and three-dimensional structure between the alleles. The crystal structures for HLA-E(G) complexed with two distinct peptides were determined, and both were compared with the HLA-E(R) structure. No significant differences in the structure of HLA-E were induced as a result of binding different peptides or by the allelic substitution at position 107. However, there were clear differences in the relative affinity for peptide of each heavy chain, which correlated with and may be explained by differences between their thermal stabilities. These differences were completely consistent with the relative levels of the HLA-E alleles on the cell surface and may indeed correlate with functional differences. This in turn may help explain the apparent balancing selection acting on this locus. | |||
HLA-E allelic variants. Correlating differential expression, peptide affinities, crystal structures, and thermal stabilities.,Strong RK, Holmes MA, Li P, Braun L, Lee N, Geraghty DE J Biol Chem. 2003 Feb 14;278(7):5082-90. Epub 2002 Oct 30. PMID:12411439<ref>PMID:12411439</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Beta-2 microglobulin|Beta-2 microglobulin]] | *[[Beta-2 microglobulin|Beta-2 microglobulin]] | ||
*[[Major histocompatibility complex|Major histocompatibility complex]] | *[[Major histocompatibility complex|Major histocompatibility complex]] | ||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Holmes, M A.]] | [[Category: Holmes, M A.]] |
Revision as of 18:00, 29 September 2014
The human non-classical major histocompatibility complex molecule HLA-EThe human non-classical major histocompatibility complex molecule HLA-E
Structural highlights
Disease[B2MG_HUMAN] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:241600]. Affected individuals show marked reduction in serum concentrations of immunoglobulin and albumin, probably due to rapid degradation.[1] 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.[2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Function[HLAE_HUMAN] Preferably binds to a peptide derived from the signal sequence of most HLA-A, -B, -C and -G molecules. [B2MG_HUMAN] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system. 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 PubMedPrevious studies of HLA-E allelic polymorphism have indicated that balancing selection may be acting to maintain two major alleles in most populations, indicating that a functional difference may exist between the alleles. The alleles differ at only one amino acid position, where an arginine at position 107 in HLA-E*0101 (E(R)) is replaced by a glycine in HLA-E*0103 (E(G)). To investigate possible functional differences, we have undertaken a study of the physical and biochemical properties of these two proteins. By comparing expression levels, we found that whereas steady-state protein levels were similar, the two alleles did in fact differ with respect to cell surface levels. To help explain this difference, we undertook studies of the relative differences in peptide affinity, complex stability, and three-dimensional structure between the alleles. The crystal structures for HLA-E(G) complexed with two distinct peptides were determined, and both were compared with the HLA-E(R) structure. No significant differences in the structure of HLA-E were induced as a result of binding different peptides or by the allelic substitution at position 107. However, there were clear differences in the relative affinity for peptide of each heavy chain, which correlated with and may be explained by differences between their thermal stabilities. These differences were completely consistent with the relative levels of the HLA-E alleles on the cell surface and may indeed correlate with functional differences. This in turn may help explain the apparent balancing selection acting on this locus. HLA-E allelic variants. Correlating differential expression, peptide affinities, crystal structures, and thermal stabilities.,Strong RK, Holmes MA, Li P, Braun L, Lee N, Geraghty DE J Biol Chem. 2003 Feb 14;278(7):5082-90. Epub 2002 Oct 30. PMID:12411439[15] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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