3qda
From Proteopedia
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- | {{STRUCTURE_3qda| PDB=3qda | SCENE= }} | ||
- | ===Crystal structure of W95L beta-2 microglobulin=== | ||
- | {{ABSTRACT_PUBMED_21663612}} | ||
- | == | + | ==Crystal structure of W95L beta-2 microglobulin== |
- | [[http://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN | + | <StructureSection load='3qda' size='340' side='right'caption='[[3qda]], [[Resolution|resolution]] 1.57Å' scene=''> |
+ | == Structural highlights == | ||
+ | <table><tr><td colspan='2'>[[3qda]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3QDA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3QDA 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]] 1.57Å</td></tr> | ||
+ | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PGE:TRIETHYLENE+GLYCOL'>PGE</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=3qda FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qda OCA], [https://pdbe.org/3qda PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3qda RCSB], [https://www.ebi.ac.uk/pdbsum/3qda PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3qda ProSAT]</span></td></tr> | ||
+ | </table> | ||
+ | == Disease == | ||
+ | [https://www.uniprot.org/uniprot/B2MG_HUMAN B2MG_HUMAN] Defects in B2M are the cause of hypercatabolic hypoproteinemia (HYCATHYP) [MIM:[https://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 == | ||
+ | [https://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. | ||
+ | <div style="background-color:#fffaf0;"> | ||
+ | == Publication Abstract from PubMed == | ||
+ | ABSTRACT: BACKGROUND: We have recently discovered that the two tryptophans of human beta2-microglobulin have distinctive roles within the structure and function of the protein. Deeply buried in the core, Trp95 is essential for folding stability, whereas Trp60, which is solvent-exposed, plays a crucial role in promoting the binding of beta2-microglobulin to the heavy chain of the class I major histocompatibility complex (MHCI). We have previously shown that the thermodynamic disadvantage of having Trp60 exposed on the surface is counter-balanced by the perfect fit between it and a cavity within the MHCI heavy chain that contributes significantly to the functional stabilization of the MHCI. Therefore, based on the peculiar differences of the two tryptophans, we have analysed the evolution of beta2-microglobulin with respect to these residues. RESULTS: Having defined the beta2-microglobulin protein family, we performed multiple sequence alignments and analysed the residue conservation in homologous proteins to generate a phylogenetic tree. Our results indicate that Trp60 is highly conserved, whereas some species have a Leu in position 95; the replacement of Trp95 with Leu destabilizes beta2-microglobulin by 1 kcal/mol and accelerates the kinetics of unfolding. Both thermodynamic and kinetic data fit with the crystallographic structure of the Trp95Leu variant, which shows how the hydrophobic cavity of the wild-type protein is completely occupied by Trp95, but is only half filled by Leu95. CONCLUSIONS: We have established that the functional Trp60 has been present within the sequence of beta2-microglobulin since the evolutionary appearance of proteins responsible for acquired immunity, whereas the structural Trp95 was selected and stabilized, most likely, for its capacity to fully occupy an internal cavity of the protein thereby creating a better stabilization of its folded state. | ||
- | + | The two tryptophans of beta2-microglobulin have distinct roles in function and folding and might represent two independent responses to evolutionary pressure.,Raimondi S, Barbarini N, Mangione P, Esposito G, Ricagno S, Bolognesi M, Zorzoli I, Marchese L, Soria C, Bellazzi R, Monti M, Stoppini M, Stefanelli M, Magni P, Bellotti V BMC Evol Biol. 2011 Jun 10;11:159. PMID:21663612<ref>PMID:21663612</ref> | |
- | + | ||
- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | + | </div> | |
+ | <div class="pdbe-citations 3qda" style="background-color:#fffaf0;"></div> | ||
==See Also== | ==See Also== | ||
- | *[[Beta-2 microglobulin|Beta-2 microglobulin]] | + | *[[Beta-2 microglobulin 3D structures|Beta-2 microglobulin 3D structures]] |
- | + | == References == | |
- | == | + | <references/> |
- | + | __TOC__ | |
+ | </StructureSection> | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
- | [[Category: | + | [[Category: Large Structures]] |
- | [[Category: | + | [[Category: Bellotti V]] |
- | [[Category: | + | [[Category: Bolognesi M]] |
- | [[Category: | + | [[Category: Ricagno S]] |
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Current revision
Crystal structure of W95L beta-2 microglobulin
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