View source for 5ecg


==Crystal structure of the BRCT domains of 53BP1 in complex with p53 and H2AX-pSer139 (gammaH2AX)==
<StructureSection load='5ecg' size='340' side='right'caption='[[5ecg]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ecg]] is a 6 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=5ECG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5ECG 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</scene>, <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=5ecg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ecg OCA], [https://pdbe.org/5ecg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ecg RCSB], [https://www.ebi.ac.uk/pdbsum/5ecg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ecg ProSAT]</span></td></tr>
</table>
== Disease ==
[https://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:[https://omim.org/entry/133239 133239].  Defects in TP53 are a cause of Li-Fraumeni syndrome (LFS) [MIM:[https://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:[https://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:[https://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:[https://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:[https://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:[https://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 ==
[https://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 ==
53BP1 plays multiple roles in mammalian DNA damage repair, mediating pathway choice and facilitating DNA double-strand break repair in heterochromatin. Although it possesses a C-terminal BRCT2 domain, commonly involved in phospho-peptide binding in other proteins, initial recruitment of 53BP1 to sites of DNA damage depends on interaction with histone post-translational modifications-H4K20me2 and H2AK13/K15ub-downstream of the early gammaH2AX phosphorylation mark of DNA damage. We now show that, contrary to current models, the 53BP1-BRCT2 domain binds gammaH2AX directly, providing a third post-translational mark regulating 53BP1 function. We find that the interaction of 53BP1 with gammaH2AX is required for sustaining the 53BP1-dependent focal concentration of activated ATM that facilitates repair of DNA double-strand breaks in heterochromatin in G1.

ATM Localization and Heterochromatin Repair Depend on Direct Interaction of the 53BP1-BRCT Domain with gammaH2AX.,Baldock RA, Day M, Wilkinson OJ, Cloney R, Jeggo PA, Oliver AW, Watts FZ, Pearl LH Cell Rep. 2015 Nov 24. pii: S2211-1247(15)01282-6. doi:, 10.1016/j.celrep.2015.10.074. PMID:26628370<ref>PMID:26628370</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5ecg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Day M]]
[[Category: Oliver AW]]
[[Category: Pearl LH]]