View source for 9kak


==CryoEM structure of LTag bound to SV40 AT half origin DNA==
<StructureSection load='9kak' size='340' side='right'caption='[[9kak]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9kak]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Macaca_mulatta_polyomavirus_1 Macaca mulatta polyomavirus 1] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9KAK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9KAK 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]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=9kak FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9kak OCA], [https://pdbe.org/9kak PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9kak RCSB], [https://www.ebi.ac.uk/pdbsum/9kak PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9kak ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LT_SV40 LT_SV40] Isoform large T antigen is a key early protein essential for both driving viral replication and inducing cellular transformation. Plays a role in viral genome replication by driving entry of quiescent cells into the cell cycle and by autoregulating the synthesis of viral early mRNA. Displays highly oncogenic activities by corrupting the host cellular checkpoint mechanisms that guard cell division and the transcription, replication, and repair of DNA. Participates in the modulation of cellular gene expression preceeding viral DNA replication. This step involves binding to host key cell cycle regulators retinoblastoma protein RB1/pRb and TP53. Induces the disassembly of host E2F1 transcription factors from RB1, thus promoting transcriptional activation of E2F1-regulated S-phase genes. Inhibits host TP53 binding to DNA, abrogating the ability of TP53 to stimulate gene expression. Plays the role of a TFIID-associated factor (TAF) in transcription initiation for all three RNA polymerases, by stabilizing the TBP-TFIIA complex on promoters. Initiates viral DNA replication and unwinding via interactions with the viral origin of replication. Binds two adjacent sites in the SV40 origin. The replication fork movement is facilitated by Large T antigen helicase activity. Activates the transcription of viral late mRNA, through host TBP and TFIIA stabilization. Interferes with histone deacetylation mediated by HDAC1, leading to activation of transcription. May inactivate the growth-suppressing properties of the E3 ubiquitin ligase CUL7.<ref>PMID:8647434</ref> <ref>PMID:9632777</ref> <ref>PMID:9488456</ref> <ref>PMID:15680424</ref> <ref>PMID:15611062</ref> <ref>PMID:17341466</ref> <ref>PMID:18922873</ref>   Isoform 17kT antigen targets host RBL2 for degradation and promotes cell proliferation. Transactivates host cyclin A promoter through its J domain.<ref>PMID:8647434</ref> <ref>PMID:9632777</ref> <ref>PMID:9488456</ref> <ref>PMID:15680424</ref> <ref>PMID:15611062</ref> <ref>PMID:17341466</ref> <ref>PMID:18922873</ref> 
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Macaca mulatta polyomavirus 1]]
[[Category: Synthetic construct]]
[[Category: Alhudhali L]]
[[Category: Clark A]]
[[Category: Danazumi AU]]
[[Category: De Biasio A]]
[[Category: Hamdan SM]]
[[Category: Savva CG]]
[[Category: Shahid T]]
[[Category: Tehseen M]]