View source for 4oxc


==Crystal structure of XIAP BIR1 domain==
<StructureSection load='4oxc' size='340' side='right'caption='[[4oxc]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4oxc]] 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=4OXC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4OXC 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]] 2.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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=4oxc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4oxc OCA], [https://pdbe.org/4oxc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4oxc RCSB], [https://www.ebi.ac.uk/pdbsum/4oxc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4oxc ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/XIAP_HUMAN XIAP_HUMAN] Defects in XIAP are the cause of lymphoproliferative syndrome X-linked type 2 (XLP2) [MIM:[https://omim.org/entry/300635 300635]. XLP is a rare immunodeficiency characterized by extreme susceptibility to infection with Epstein-Barr virus (EBV). Symptoms include severe or fatal mononucleosis, acquired hypogammaglobulinemia, pancytopenia and malignant lymphoma.<ref>PMID:17080092</ref> 
== Function ==
[https://www.uniprot.org/uniprot/XIAP_HUMAN XIAP_HUMAN] Multi-functional protein which regulates not only caspases and apoptosis, but also modulates inflammatory signaling and immunity, copper homeostasis, mitogenic kinase signaling, cell proliferation, as well as cell invasion and metastasis. Acts as a direct caspase inhibitor. Directly bind to the active site pocket of CASP3 and CASP7 and obstructs substrate entry. Inactivates CASP9 by keeping it in a monomeric, inactive state. Acts as an E3 ubiquitin-protein ligase regulating NF-kappa-B signaling and the target proteins for its E3 ubiquitin-protein ligase activity include: RIPK1, CASP3, CASP7, CASP8, CASP9, MAP3K2/MEKK2, DIABLO/SMAC, AIFM1, CCS and BIRC5/survivin. Ubiquitinion of CCS leads to enhancement of its chaperone activity toward its physiologic target, SOD1, rather than proteasomal degradation. Ubiquitinion of MAP3K2/MEKK2 and AIFM1 does not lead to proteasomal degradation. Plays a role in copper homeostasis by ubiquitinationg COMMD1 and promoting its proteasomal degradation. Can also function as E3 ubiquitin-protein ligase of the NEDD8 conjugation pathway, targeting effector caspases for neddylation and inactivation. Regulates the BMP signaling pathway and the SMAD and MAP3K7/TAK1 dependent pathways leading to NF-kappa-B and JNK activation. Acts as an important regulator of innate immune signaling via regulation of Nodlike receptors (NLRs). Protects cells from spontaneous formation of the ripoptosome, a large multi-protein complex that has the capability to kill cancer cells in a caspase-dependent and caspase-independent manner. Suppresses ripoptosome formation by ubiquitinating RIPK1 and CASP8. Acts as a positive regulator of Wnt signaling and ubiquitinates TLE1, TLE2, TLE3, TLE4 and AES. Ubiquitination of TLE3 results in inhibition of its interaction with TCF7L2/TCF4 thereby allowing efficient recruitment and binding of the transcriptional coactivator beta-catenin to TCF7L2/TCF4 that is required to initiate a Wnt-specific transcriptional program.<ref>PMID:9230442</ref> <ref>PMID:11447297</ref> <ref>PMID:12121969</ref> <ref>PMID:14685266</ref> <ref>PMID:14645242</ref> <ref>PMID:17967870</ref> <ref>PMID:19473982</ref> <ref>PMID:21145488</ref> <ref>PMID:20154138</ref> <ref>PMID:22103349</ref> <ref>PMID:22304967</ref> <ref>PMID:17560374</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Inhibitor of Apoptosis Proteins (IAPs) are the target of extensive research in the field of cancer therapy since they regulate apoptosis and cell survival. Smac-mimetics, the most promising IAP-targeting compounds specifically recognize the IAP-BIR3 domain and promote apoptosis, competing with caspases for IAP binding. Furthermore, Smac-mimetics interfere with the NF-kappaB survival pathway, inducing cIAP1 and cIAP2 degradation through an auto-ubiquitination process. It has been shown that the XIAP-BIR1 (X-BIR1) domain is involved in the interaction with TAB1, an upstream adaptor for TAK1 kinase activation, which in turn couples with the NF-kappaB survival pathway. Preventing X-BIR1 dimerization abolishes XIAP-mediated NF-kappaB activation, thus implicating a proximity-induced mechanism for TAK1 activation. In this context, in a systematic search for a molecule capable of impairing X-BIR1/TAB1 assembly, we identified the compound NF023. Here we report the crystal structure of the human X-BIR1 domain in the absence and in the presence of NF023, as a starting concept for the design of novel BIR1-specific compounds acting synergistically with existing pro-apoptotic drugs in cancer therapy. Proteins 2015. (c) 2015 Wiley Periodicals, Inc.

NF023 binding to XIAP-BIR1: Searching drugs for regulation of the NF-kappaB pathway.,Cossu F, Milani M, Grassi S, Malvezzi F, Corti A, Bolognesi M, Mastrangelo E Proteins. 2015 Jan 23. doi: 10.1002/prot.24766. PMID:25619915<ref>PMID:25619915</ref>

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

==See Also==
*[[Ubiquitin protein ligase 3D structures|Ubiquitin protein ligase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cossu F]]
[[Category: Mastrangelo E]]
[[Category: Milani M]]