View source for 4r9h


==Crystal structure of dimeric S33C beta-2 microglobulin mutant at 1.9 Angstrom resolution==
<StructureSection load='4r9h' size='340' side='right'caption='[[4r9h]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4r9h]] is a 4 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=4R9H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4R9H 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]] 1.9&#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=4r9h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4r9h OCA], [https://pdbe.org/4r9h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4r9h RCSB], [https://www.ebi.ac.uk/pdbsum/4r9h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4r9h 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 ==
Early oligomers are crucial in amyloid aggregation; however, due to their transient nature they are among the least structurally characterized species. We focused on the amyloidogenic protein beta2-microglobulin (beta2m) whose early oligomers are still a matter of debate. An intermolecular interaction between D strands of facing beta2m molecules was repeatedly observed, suggesting that such interface may be relevant for beta2m dimerization. In this study, by mutating Ser33 to Cys, and assembling the disulphide-stabilized beta2m homodimer (DimC33), such DD strand interface was locked. Although the isolated DimC33 display a stability similar to wt beta2m under native conditions, it shows enhanced amyloid aggregation propensity. Three distinct crystal structures of DimC33 suggest that dimerization through the DD interface is instrumental for enhancing DimC33 aggregation propensity. Furthermore, the crystal structure of DimC33 in complex with the amyloid-specific dye Thioflavin-T pinpoints a second interface, which likely participates in the first steps of beta2m aggregation. The present data provide new insight into beta2m early steps of amyloid aggregation.

A covalent homodimer probing early oligomers along amyloid aggregation.,Halabelian L, Relini A, Barbiroli A, Penco A, Bolognesi M, Ricagno S Sci Rep. 2015 Sep 30;5:14651. doi: 10.1038/srep14651. PMID:26420657<ref>PMID:26420657</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4r9h" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-2 microglobulin 3D structures|Beta-2 microglobulin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Bolognesi M]]
[[Category: Halabelian L]]
[[Category: Ricagno S]]