View source for 2zi0


==Crystal structure of Tav2b/siRNA complex==
<StructureSection load='2zi0' size='340' side='right'caption='[[2zi0]], [[Resolution|resolution]] 2.82&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zi0]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Tomato_aspermy_virus Tomato aspermy virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZI0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZI0 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]] 2.82&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=2zi0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zi0 OCA], [https://pdbe.org/2zi0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zi0 RCSB], [https://www.ebi.ac.uk/pdbsum/2zi0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zi0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/2B_TAV 2B_TAV] Acts as suppressor of RNA-mediated gene silencing, also known as post-transcriptional gene silencing (PTGS), a mechanism of plant viral defense that limits the accumulation of viral RNAs. Forms a homodimer to measure siRNA duplex in a length-preferencemode. Binds to both siRNA duplexes (19bp) and long siRNA duplexes (30bp).<ref>PMID:10329615</ref> <ref>PMID:8291242</ref> <ref>PMID:9010309</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/zi/2zi0_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2zi0 ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
The 2b proteins encoded by cucumovirus act as post-transcriptional gene silencing suppressors to counter host defence during infection. Here we report the crystal structure of Tomato aspermy virus 2b (TAV2b) protein bound to a 19 bp small interfering RNA (siRNA) duplex. TAV2b adopts an all alpha-helix structure and forms a homodimer to measure siRNA duplex in a length-preference mode. TAV2b has a pair of hook-like structures to recognize simultaneously two alpha-helical turns of A-form RNA duplex by fitting its alpha-helix backbone into two adjacent major grooves of siRNA duplex. The conserved pi-stackings between tryptophan and the 5'-terminal base of siRNA duplex from both ends enhance the recognition. TAV2b further oligomerizes to form a dimer of dimers through the conserved leucine-zipper-like motif at its amino-terminal alpha-helix. Biochemical experiments suggest that TAV2b might interfere with the post-transcriptional gene silencing pathway by directly binding to siRNA duplex.

Structural basis for RNA-silencing suppression by Tomato aspermy virus protein 2b.,Chen HY, Yang J, Lin C, Yuan YA EMBO Rep. 2008 Aug;9(8):754-60. Epub 2008 Jul 4. PMID:18600235<ref>PMID:18600235</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 2zi0" style="background-color:#fffaf0;"></div>

==See Also==
*[[Flock house virus protein B2|Flock house virus protein B2]]
*[[P19|P19]]
*[[RNA silencing suppressor|RNA silencing suppressor]]
*[[Suppression of RNA Silencing by Viruses|Suppression of RNA Silencing by Viruses]]
*[[Tomato aspermy virus protein 2b Suppression of RNA Silencing|Tomato aspermy virus protein 2b Suppression of RNA Silencing]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Tomato aspermy virus]]
[[Category: Chen H-Y]]
[[Category: Yuan YA]]