View source for 2ijx


==Crystal structure of PCNA3 monomer from Sulfolobus solfataricus.==
<StructureSection load='2ijx' size='340' side='right'caption='[[2ijx]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2ijx]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus_P2 Saccharolobus solfataricus P2]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IJX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2IJX 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</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=2ijx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ijx OCA], [https://pdbe.org/2ijx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ijx RCSB], [https://www.ebi.ac.uk/pdbsum/2ijx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ijx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PCNA3_SACS2 PCNA3_SACS2] One of the sliding clamp subunits that acts as a moving platform for DNA processing. Responsible for tethering the catalytic subunit of DNA polymerase to DNA during high-speed replication. DNA polymerase I, DNA ligase and the flap endonuclease may be constitutively associated with the PCNA heterotrimer forming a scanning complex able to couple DNA synthesis and Okazaki fragment maturation. Heterotrimer stimulates the Holliday junction resolvase Hjc.<ref>PMID:12535540</ref> <ref>PMID:17011573</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/ij/2ijx_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=2ijx ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
DNA sliding clamps form an oligomeric ring encircling DNA and serve as a moving platform for DNA-processing proteins. The opening and closing of a sliding-clamp ring is essential to load the clamp onto DNA in order to perform its functions. The molecular details of how clamp rings open and enclose DNA are still not clear. Three PCNA homologues have been found in Sulfolobus solfataricus which form a heterotrimer. Taking advantage of their hetero-oligomeric nature, the structures of the PCNAs in monomeric PCNA3, dimeric PCNA1-PCNA2 and trimeric PCNA1-PCNA2-PCNA3 forms were determined at resolutions of 2.6-1.9 A. The distinct oligomeric structures represent different stages in ring formation, which were verified in solution by ultracentrifugation analysis. The heterodimer opens in a V-shape of 130 degrees , while the heterotrimers form a ring with a 120 degrees rotation between monomers. The association of a rigid PCNA3 monomer with an opened PCNA1-PCNA2 heterodimer closes the ring and introduces a spring tension in the PCNA1-PCNA2 interface, thus bending the nine-stranded intermolecular beta-sheet to fit the 120 degrees rotation. The release of the spring tension as PCNA3 dissociates from the ring may facilitate ring opening. The structural features in different assemblies present a molecular model for clamp ring assembly and opening.

Structures of monomeric, dimeric and trimeric PCNA: PCNA-ring assembly and opening.,Hlinkova V, Xing G, Bauer J, Shin YJ, Dionne I, Rajashankar KR, Bell SD, Ling H Acta Crystallogr D Biol Crystallogr. 2008 Sep;64(Pt 9):941-9. Epub 2008, Aug 13. PMID:18703842<ref>PMID:18703842</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 2ijx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Proliferating cell nuclear antigen 3D structures|Proliferating cell nuclear antigen 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharolobus solfataricus P2]]
[[Category: Hlinkova V]]
[[Category: Ling H]]