View source for 6qzt


==Crystal structure of Csx1 from Sulfolobus islandicus orthorhombic form==
<StructureSection load='6qzt' size='340' side='right'caption='[[6qzt]], [[Resolution|resolution]] 2.93&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6qzt]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Sulfolobus_islandicus_REY15A Sulfolobus islandicus REY15A]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6QZT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6QZT 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]] 2.93&#8491;</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=6qzt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6qzt OCA], [https://pdbe.org/6qzt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6qzt RCSB], [https://www.ebi.ac.uk/pdbsum/6qzt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6qzt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/F0NE21_SULIR F0NE21_SULIR] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Type III CRISPR-Cas multisubunit complexes cleave ssRNA and ssDNA. These activities promote the generation of cyclic oligoadenylate (cOA), which activates associated CRISPR-Cas RNases from the Csm/Csx families, triggering a massive RNA decay to provide immunity from genetic invaders. Here we present the structure of Sulfolobus islandicus (Sis) Csx1-cOA4 complex revealing the allosteric activation of its RNase activity. SisCsx1 is a hexamer built by a trimer of dimers. Each dimer forms a cOA4 binding site and a ssRNA catalytic pocket. cOA4 undergoes a conformational change upon binding in the second messenger binding site activating ssRNA degradation in the catalytic pockets. Activation is transmitted in an allosteric manner through an intermediate HTH domain, which joins the cOA4 and catalytic sites. The RNase functions in a sequential cooperative fashion, hydrolyzing phosphodiester bonds in 5'-C-C-3'. The degradation of cOA4 by Ring nucleases deactivates SisCsx1, suggesting that this enzyme could be employed in biotechnological applications.

Structure of Csx1-cOA4 complex reveals the basis of RNA decay in Type III-B CRISPR-Cas.,Molina R, Stella S, Feng M, Sofos N, Jauniskis V, Pozdnyakova I, Lopez-Mendez B, She Q, Montoya G Nat Commun. 2019 Sep 20;10(1):4302. doi: 10.1038/s41467-019-12244-z. PMID:31541109<ref>PMID:31541109</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6qzt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Sulfolobus islandicus REY15A]]
[[Category: Molina R]]
[[Category: Montoya G]]
[[Category: Sofos N]]
[[Category: Stella S]]