4xr8
From Proteopedia
(Difference between revisions)
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- | ''' | + | ==Crystal structure of the HPV16 E6/E6AP/p53 ternary complex at 2.25 A resolution== |
+ | <StructureSection load='4xr8' size='340' side='right' caption='[[4xr8]], [[Resolution|resolution]] 2.25Å' scene=''> | ||
+ | == Structural highlights == | ||
+ | <table><tr><td colspan='2'>[[4xr8]] is a 6 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XR8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4XR8 FirstGlance]. <br> | ||
+ | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MAL:MALTOSE'>MAL</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | ||
+ | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4giz|4giz]]</td></tr> | ||
+ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4xr8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xr8 OCA], [http://pdbe.org/4xr8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4xr8 RCSB], [http://www.ebi.ac.uk/pdbsum/4xr8 PDBsum]</span></td></tr> | ||
+ | </table> | ||
+ | == Disease == | ||
+ | [[http://www.uniprot.org/uniprot/P53_HUMAN P53_HUMAN]] Note=TP53 is found in increased amounts in a wide variety of transformed cells. TP53 is frequently mutated or inactivated in about 60% of cancers. TP53 defects are found in Barrett metaplasia a condition in which the normally stratified squamous epithelium of the lower esophagus is replaced by a metaplastic columnar epithelium. The condition develops as a complication in approximately 10% of patients with chronic gastroesophageal reflux disease and predisposes to the development of esophageal adenocarcinoma. Defects in TP53 are a cause of esophageal cancer (ESCR) [MIM:[http://omim.org/entry/133239 133239]]. Defects in TP53 are a cause of Li-Fraumeni syndrome (LFS) [MIM:[http://omim.org/entry/151623 151623]]. LFS is an autosomal dominant familial cancer syndrome that in its classic form is defined by the existence of a proband affected by a sarcoma before 45 years with a first degree relative affected by any tumor before 45 years and another first degree relative with any tumor before 45 years or a sarcoma at any age. Other clinical definitions for LFS have been proposed (PubMed:8118819 and PubMed:8718514) and called Li-Fraumeni like syndrome (LFL). In these families affected relatives develop a diverse set of malignancies at unusually early ages. Four types of cancers account for 80% of tumors occurring in TP53 germline mutation carriers: breast cancers, soft tissue and bone sarcomas, brain tumors (astrocytomas) and adrenocortical carcinomas. Less frequent tumors include choroid plexus carcinoma or papilloma before the age of 15, rhabdomyosarcoma before the age of 5, leukemia, Wilms tumor, malignant phyllodes tumor, colorectal and gastric cancers.<ref>PMID:10570149</ref> <ref>PMID:1933902</ref> <ref>PMID:1978757</ref> <ref>PMID:2259385</ref> <ref>PMID:1737852</ref> <ref>PMID:1565144</ref> <ref>PMID:7887414</ref> <ref>PMID:8825920</ref> <ref>PMID:9452042</ref> <ref>PMID:10484981</ref> Defects in TP53 are involved in head and neck squamous cell carcinomas (HNSCC) [MIM:[http://omim.org/entry/275355 275355]]; also known as squamous cell carcinoma of the head and neck. Defects in TP53 are a cause of lung cancer (LNCR) [MIM:[http://omim.org/entry/211980 211980]]. LNCR is a common malignancy affecting tissues of the lung. The most common form of lung cancer is non-small cell lung cancer (NSCLC) that can be divided into 3 major histologic subtypes: squamous cell carcinoma, adenocarcinoma, and large cell lung cancer. NSCLC is often diagnosed at an advanced stage and has a poor prognosis. Defects in TP53 are a cause of choroid plexus papilloma (CPLPA) [MIM:[http://omim.org/entry/260500 260500]]. Choroid plexus papilloma is a slow-growing benign tumor of the choroid plexus that often invades the leptomeninges. In children it is usually in a lateral ventricle but in adults it is more often in the fourth ventricle. Hydrocephalus is common, either from obstruction or from tumor secretion of cerebrospinal fluid. If it undergoes malignant transformation it is called a choroid plexus carcinoma. Primary choroid plexus tumors are rare and usually occur in early childhood.<ref>PMID:12085209</ref> Defects in TP53 are a cause of adrenocortical carcinoma (ADCC) [MIM:[http://omim.org/entry/202300 202300]]. ADCC is a rare childhood tumor of the adrenal cortex. It occurs with increased frequency in patients with the Beckwith-Wiedemann syndrome and is a component tumor in Li-Fraumeni syndrome.<ref>PMID:11481490</ref> Defects in TP53 are the cause of susceptibility to basal cell carcinoma 7 (BCC7) [MIM:[http://omim.org/entry/614740 614740]]. A common malignant skin neoplasm that typically appears on hair-bearing skin, most commonly on sun-exposed areas. It is slow growing and rarely metastasizes, but has potentialities for local invasion and destruction. It usually develops as a flat, firm, pale area that is small, raised, pink or red, translucent, shiny, and waxy, and the area may bleed following minor injury. Tumor size can vary from a few millimeters to several centimeters in diameter.<ref>PMID:21946351</ref> | ||
+ | == Function == | ||
+ | [[http://www.uniprot.org/uniprot/MALE_ECOLI MALE_ECOLI]] Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides. [[http://www.uniprot.org/uniprot/VE6_HPV16 VE6_HPV16]] Plays a major role in the induction and maintenance of cellular transformation. Acts mainly as an oncoprotein by stimulating the destruction of many host cell key regulatory proteins. E6 associates with host E6-AP ubiquitin-protein ligase, and inactivates tumor suppressors TP53 and TP73 by targeting them to the 26S proteasome for degradation. In turn, DNA damage and chromosomal instabilities increase and lead to cell proliferation and cancer development. The complex E6/E6P targets several other substrates to degradation via the proteasome including host NFX1-91, a repressor of human telomerase reverse transcriptase (hTERT). The resulting increased expression of hTERT prevents the shortening of telomere length leading to cell immortalization. Other cellular targets including Bak, Fas-associated death domain-containing protein (FADD) and procaspase 8, are degraded by E6/E6AP causing inhibition of apoptosis. E6 also inhibits immune response by interacting with host IRF3 and TYK2. These interactions prevent IRF3 transcriptional activities and inhibit TYK2-mediated JAK-STAT activation by interferon alpha resulting in inhibition of the interferon signaling pathway.<ref>PMID:8598912</ref> <ref>PMID:9649509</ref> <ref>PMID:10523853</ref> [[http://www.uniprot.org/uniprot/P53_HUMAN P53_HUMAN]] Acts as a tumor suppressor in many tumor types; induces growth arrest or apoptosis depending on the physiological circumstances and cell type. Involved in cell cycle regulation as a trans-activator that acts to negatively regulate cell division by controlling a set of genes required for this process. One of the activated genes is an inhibitor of cyclin-dependent kinases. Apoptosis induction seems to be mediated either by stimulation of BAX and FAS antigen expression, or by repression of Bcl-2 expression. In cooperation with mitochondrial PPIF is involved in activating oxidative stress-induced necrosis; te function is largely independent of transcription. Induces the transcription of long intergenic non-coding RNA p21 (lincRNA-p21) and lincRNA-Mkln1. LincRNA-p21 participates in TP53-dependent transcriptional repression leading to apoptosis and seem to have to effect on cell-cycle regulation. Implicated in Notch signaling cross-over. Prevents CDK7 kinase activity when associated to CAK complex in response to DNA damage, thus stopping cell cycle progression. Isoform 2 enhances the transactivation activity of isoform 1 from some but not all TP53-inducible promoters. Isoform 4 suppresses transactivation activity and impairs growth suppression mediated by isoform 1. Isoform 7 inhibits isoform 1-mediated apoptosis.<ref>PMID:9840937</ref> <ref>PMID:11025664</ref> <ref>PMID:12810724</ref> <ref>PMID:15186775</ref> <ref>PMID:15340061</ref> <ref>PMID:17317671</ref> <ref>PMID:17349958</ref> <ref>PMID:19556538</ref> <ref>PMID:20673990</ref> <ref>PMID:20959462</ref> <ref>PMID:22726440</ref> | ||
+ | <div style="background-color:#fffaf0;"> | ||
+ | == Publication Abstract from PubMed == | ||
+ | The p53 pro-apoptotic tumour suppressor is mutated or functionally altered in most cancers. In epithelial tumours induced by 'high-risk' mucosal human papilloma viruses, including human cervical carcinoma and a growing number of head-and-neck cancers, p53 is degraded by the viral oncoprotein E6 (ref. 2). In this process, E6 binds to a short leucine (L)-rich LxxLL consensus sequence within the cellular ubiquitin ligase E6AP. Subsequently, the E6/E6AP heterodimer recruits and degrades p53 (ref. 4). Neither E6 nor E6AP are separately able to recruit p53 (refs 3, 5), and the precise mode of assembly of E6, E6AP and p53 is unknown. Here we solve the crystal structure of a ternary complex comprising full-length human papilloma virus type 16 (HPV-16) E6, the LxxLL motif of E6AP and the core domain of p53. The LxxLL motif of E6AP renders the conformation of E6 competent for interaction with p53 by structuring a p53-binding cleft on E6. Mutagenesis of critical positions at the E6-p53 interface disrupts p53 degradation. The E6-binding site of p53 is distal from previously described DNA- and protein-binding surfaces of the core domain. This suggests that, in principle, E6 may avoid competition with cellular factors by targeting both free and bound p53 molecules. The E6/E6AP/p53 complex represents a prototype of viral hijacking of both the ubiquitin-mediated protein degradation pathway and the p53 tumour suppressor pathway. The present structure provides a framework for the design of inhibitory therapeutic strategies against oncogenesis mediated by human papilloma virus. | ||
- | + | Structure of the E6/E6AP/p53 complex required for HPV-mediated degradation of p53.,Martinez-Zapien D, Ruiz FX, Poirson J, Mitschler A, Ramirez J, Forster A, Cousido-Siah A, Masson M, Vande Pol S, Podjarny A, Trave G, Zanier K Nature. 2016 Jan 28;529(7587):541-5. doi: 10.1038/nature16481. Epub 2016 Jan 20. PMID:26789255<ref>PMID:26789255</ref> | |
- | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
- | + | </div> | |
- | + | <div class="pdbe-citations 4xr8" style="background-color:#fffaf0;"></div> | |
- | [[Category: | + | == References == |
+ | <references/> | ||
+ | __TOC__ | ||
+ | </StructureSection> | ||
+ | [[Category: Martinez-Zapien, D]] | ||
[[Category: Mitschler, A]] | [[Category: Mitschler, A]] | ||
+ | [[Category: Podjarny, A]] | ||
+ | [[Category: Ruiz, F X]] | ||
[[Category: Trave, G]] | [[Category: Trave, G]] | ||
- | [[Category: Podjarny, A]] | ||
[[Category: Zanier, K]] | [[Category: Zanier, K]] | ||
- | [[Category: | + | [[Category: E6 oncoprotein]] |
- | [[Category: | + | [[Category: Human papillomavirus 16]] |
+ | [[Category: P53 degradation]] | ||
+ | [[Category: Tumor suppressor p53]] | ||
+ | [[Category: Ubiquitin-ligase e6ap]] | ||
+ | [[Category: Viral protein- antitumor protein complex]] | ||
+ | [[Category: Viral protein-antitumor protein]] |
Revision as of 15:47, 3 February 2016
Crystal structure of the HPV16 E6/E6AP/p53 ternary complex at 2.25 A resolution
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