View source for 1un6


==THE CRYSTAL STRUCTURE OF A ZINC FINGER - RNA COMPLEX REVEALS TWO MODES OF MOLECULAR RECOGNITION==
<StructureSection load='1un6' size='340' side='right'caption='[[1un6]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1un6]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Xenopus_laevis Xenopus laevis]. The March 2007 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Zinc Fingers''  by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2007_3 10.2210/rcsb_pdb/mom_2007_3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UN6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1UN6 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]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=1un6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1un6 OCA], [https://pdbe.org/1un6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1un6 RCSB], [https://www.ebi.ac.uk/pdbsum/1un6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1un6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TF3A_XENLA TF3A_XENLA] Acts as both a positive transcription factor for 5S RNA genes and a specific RNA binding protein that complexes with 5S RNA in oocytes to form the 7S ribonucleoprotein storage particle. May play an essential role in the developmental change in 5S RNA gene expression. Interacts with the internal control region (ICR) of approximately 50 bases within the 5S RNA genes, is required for correct transcription of these genes by RNA polymerase III. Also binds the transcribed 5S RNA's.
== 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/un/1un6_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1un6 ConSurf].
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== Publication Abstract from PubMed ==
Zinc-finger proteins of the classical Cys2His2 type are the most frequently used class of transcription factor and account for about 3% of genes in the human genome. The zinc-finger motif was discovered during biochemical studies on the transcription factor TFIIIA, which regulates the 5S ribosomal RNA genes of Xenopus laevis. Zinc-fingers mostly interact with DNA, but TFIIIA binds not only specifically to the promoter DNA, but also to 5S RNA itself. Increasing evidence indicates that zinc-fingers are more widely used to recognize RNA. There have been numerous structural studies on DNA binding, but none on RNA binding by zinc-finger proteins. Here we report the crystal structure of a three-finger complex with 61 bases of RNA, derived from the central regions of the complete nine-finger TFIIIA-5S RNA complex. The structure reveals two modes of zinc-finger binding, both of which differ from that in common use for DNA: first, the zinc-fingers interact with the backbone of a double helix; and second, the zinc-fingers specifically recognize individual bases positioned for access in otherwise intricately folded 'loop' regions of the RNA.

Crystal structure of a zinc-finger-RNA complex reveals two modes of molecular recognition.,Lu D, Searles MA, Klug A Nature. 2003 Nov 6;426(6962):96-100. PMID:14603324<ref>PMID:14603324</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: RCSB PDB Molecule of the Month]]
[[Category: Xenopus laevis]]
[[Category: Zinc Fingers]]
[[Category: Klug A]]
[[Category: Lu D]]
[[Category: Searles MA]]