View source for 9v33


==Calypso/Asx/NCP-ub complex==
<StructureSection load='9v33' size='340' side='right'caption='[[9v33]], [[Resolution|resolution]] 5.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9v33]] is a 15 chain structure with sequence from [https://en.wikipedia.org/wiki/Drosophila_melanogaster Drosophila melanogaster], [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli], [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9V33 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9V33 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 5.9&#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=9v33 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9v33 OCA], [https://pdbe.org/9v33 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9v33 RCSB], [https://www.ebi.ac.uk/pdbsum/9v33 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9v33 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A310TTQ1_XENLA A0A310TTQ1_XENLA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Polycomb repressive complex 1 (PRC1) and PR-DUB constitute a canonical pair of histone-modifying enzymes that deposit and remove monoubiquitinated H2A at lysine 119 (H2AK119ub1), serving as a model of dynamic epigenetic regulation. In humans, PR-DUB, composed of BAP1 and ASXL1, functions as a monomeric complex, while the Drosophila homolog Calypso/Asx forms a bidentate dimer (Calypso(2): Asx(2)) with an unclear chromatin engagement mechanism. Here, we present its cryo-EM structure bound to a nucleosome, revealing the molecular basis of interaction. Surprisingly, only one Calypso/Asx unit engages the nucleosome in a conformation similar to human BAP1/ASXL1, while the second remains disengaged. Structural and biochemical analysis of the positively charged Calypso C terminus suggests a "spreading" potential of the bidentate complex along chromatin, which was validated in vitro using nucleosome arrays. These findings support a model in which the bidentate Calypso/Asx complex enables processive deubiquitination along chromatin via alternating or cooperative engagement.

Structural basis of nucleosome deubiquitination by the bidentate Calypso/Asx complex.,Wang C, Sun F, Zhao H, Zhang N, Guan J, Zhou Y, Shuai W, Zheng H, He J iScience. 2026 Feb 10;29(3):114958. doi: 10.1016/j.isci.2026.114958. eCollection , 2026 Mar 20. PMID:41782825<ref>PMID:41782825</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9v33" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Drosophila melanogaster]]
[[Category: Escherichia coli]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Xenopus laevis]]
[[Category: He J]]
[[Category: Wang C]]