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1n25

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Revision as of 08:08, 31 January 2018

Crystal structure of the SV40 Large T antigen helicase domain

Structural highlights

1n25 is a 2 chain structure. The November 2003 RCSB PDB Molecule of the Month feature on Simian Virus 40 by David S. Goodsell is 10.2210/rcsb_pdb/mom_2003_11. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[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.^[1] ^[2] ^[3] ^[4] ^[5] ^[6] ^[7] Isoform 17kT antigen targets host RBL2 for degradation and promotes cell proliferation. Transactivates host cyclin A promoter through its J domain.^[8] ^[9] ^[10] ^[11] ^[12] ^[13] ^[14]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The oncoprotein large tumour antigen (LTag) is encoded by the DNA tumour virus simian virus 40. LTag transforms cells and induces tumours in animals by altering the functions of tumour suppressors (including pRB and p53) and other key cellular proteins. LTag is also a molecular machine that distorts/melts the replication origin of the viral genome and unwinds duplex DNA. LTag therefore seems to be a functional homologue of the eukaryotic minichromosome maintenance (MCM) complex. Here we present the X-ray structure of a hexameric LTag with DNA helicase activity. The structure identifies the p53-binding surface and reveals the structural basis of hexamerization. The hexamer contains a long, positively charged channel with an unusually large central chamber that binds both single-stranded and double-stranded DNA. The hexamer organizes into two tiers that can potentially rotate relative to each other through connecting alpha-helices to expand/constrict the channel, producing an 'iris' effect that could be used for distorting or melting the origin and unwinding DNA at the replication fork.

Structure of the replicative helicase of the oncoprotein SV40 large tumour antigen.,Li D, Zhao R, Lilyestrom W, Gai D, Zhang R, DeCaprio JA, Fanning E, Jochimiak A, Szakonyi G, Chen XS Nature. 2003 May 29;423(6939):512-8. PMID:12774115^[15]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Damania B, Alwine JC. TAF-like function of SV40 large T antigen. Genes Dev. 1996 Jun 1;10(11):1369-81. PMID:8647434
↑ Damania B, Lieberman P, Alwine JC. Simian virus 40 large T antigen stabilizes the TATA-binding protein-TFIIA complex on the TATA element. Mol Cell Biol. 1998 Jul;18(7):3926-35. PMID:9632777
↑ Zalvide J, Stubdal H, DeCaprio JA. The J domain of simian virus 40 large T antigen is required to functionally inactivate RB family proteins. Mol Cell Biol. 1998 Mar;18(3):1408-15. PMID:9488456
↑ Skoczylas C, Henglein B, Rundell K. PP2A-dependent transactivation of the cyclin A promoter by SV40 ST is mediated by a cell cycle-regulated E2F site. Virology. 2005 Feb 20;332(2):596-601. PMID:15680424 doi:10.1016/j.virol.2004.12.017
↑ Welcker M, Clurman BE. The SV40 large T antigen contains a decoy phosphodegron that mediates its interactions with Fbw7/hCdc4. J Biol Chem. 2005 Mar 4;280(9):7654-8. Epub 2004 Dec 20. PMID:15611062 doi:10.1074/jbc.M413377200
↑ Valls E, Blanco-Garcia N, Aquizu N, Piedra D, Estaras C, de la Cruz X, Martinez-Balbas MA. Involvement of chromatin and histone deacetylation in SV40 T antigen transcription regulation. Nucleic Acids Res. 2007;35(6):1958-68. Epub 2007 Mar 6. PMID:17341466 doi:gkl1113
↑ Hein J, Boichuk S, Wu J, Cheng Y, Freire R, Jat PS, Roberts TM, Gjoerup OV. Simian virus 40 large T antigen disrupts genome integrity and activates a DNA damage response via Bub1 binding. J Virol. 2009 Jan;83(1):117-27. doi: 10.1128/JVI.01515-08. Epub 2008 Oct 15. PMID:18922873 doi:10.1128/JVI.01515-08
↑ Damania B, Alwine JC. TAF-like function of SV40 large T antigen. Genes Dev. 1996 Jun 1;10(11):1369-81. PMID:8647434
↑ Damania B, Lieberman P, Alwine JC. Simian virus 40 large T antigen stabilizes the TATA-binding protein-TFIIA complex on the TATA element. Mol Cell Biol. 1998 Jul;18(7):3926-35. PMID:9632777
↑ Zalvide J, Stubdal H, DeCaprio JA. The J domain of simian virus 40 large T antigen is required to functionally inactivate RB family proteins. Mol Cell Biol. 1998 Mar;18(3):1408-15. PMID:9488456
↑ Skoczylas C, Henglein B, Rundell K. PP2A-dependent transactivation of the cyclin A promoter by SV40 ST is mediated by a cell cycle-regulated E2F site. Virology. 2005 Feb 20;332(2):596-601. PMID:15680424 doi:10.1016/j.virol.2004.12.017
↑ Welcker M, Clurman BE. The SV40 large T antigen contains a decoy phosphodegron that mediates its interactions with Fbw7/hCdc4. J Biol Chem. 2005 Mar 4;280(9):7654-8. Epub 2004 Dec 20. PMID:15611062 doi:10.1074/jbc.M413377200
↑ Valls E, Blanco-Garcia N, Aquizu N, Piedra D, Estaras C, de la Cruz X, Martinez-Balbas MA. Involvement of chromatin and histone deacetylation in SV40 T antigen transcription regulation. Nucleic Acids Res. 2007;35(6):1958-68. Epub 2007 Mar 6. PMID:17341466 doi:gkl1113
↑ Hein J, Boichuk S, Wu J, Cheng Y, Freire R, Jat PS, Roberts TM, Gjoerup OV. Simian virus 40 large T antigen disrupts genome integrity and activates a DNA damage response via Bub1 binding. J Virol. 2009 Jan;83(1):117-27. doi: 10.1128/JVI.01515-08. Epub 2008 Oct 15. PMID:18922873 doi:10.1128/JVI.01515-08
↑ Li D, Zhao R, Lilyestrom W, Gai D, Zhang R, DeCaprio JA, Fanning E, Jochimiak A, Szakonyi G, Chen XS. Structure of the replicative helicase of the oncoprotein SV40 large tumour antigen. Nature. 2003 May 29;423(6939):512-8. PMID:12774115 doi:10.1038/nature01691

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1n25"

@@ Line 1: / Line 1: @@
 ==Crystal structure of the SV40 Large T antigen helicase domain==
 <StructureSection load='1n25' size='340' side='right' caption='[[1n25]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[1n25]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Polyomavirus_maccacae Polyomavirus maccacae]. The November 2003 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Simian Virus 40''  by David S. Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2003_11 10.2210/rcsb_pdb/mom_2003_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N25 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1N25 FirstGlance]. <br>
+<table><tr><td colspan='2'>[[1n25]] is a 2 chain structure. The November 2003 RCSB PDB [http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Simian Virus 40''  by David S. Goodsell is [http://dx.doi.org/10.2210/rcsb_pdb/mom_2003_11 10.2210/rcsb_pdb/mom_2003_11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N25 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1N25 FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1n25 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n25 OCA], [http://pdbe.org/1n25 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1n25 RCSB], [http://www.ebi.ac.uk/pdbsum/1n25 PDBsum]</span></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=1n25 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n25 OCA], [http://pdbe.org/1n25 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1n25 RCSB], [http://www.ebi.ac.uk/pdbsum/1n25 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1n25 ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 12: / Line 13: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/n2/1n25_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/n2/1n25_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
@@ Line 27: / Line 28: @@
 </div>
 <div class="pdbe-citations 1n25" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[Large T Antigen|Large T Antigen]]
 == References ==
 <references/>
 __TOC__
 </StructureSection>
-[[Category: Polyomavirus maccacae]]
 [[Category: RCSB PDB Molecule of the Month]]
 [[Category: Simian Virus 40]]

1n25

From Proteopedia

Revision as of 08:08, 31 January 2018

Crystal structure of the SV40 Large T antigen helicase domain

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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