View source for 6sce


==Structure of a Type III CRISPR defence DNA nuclease activated by cyclic oligoadenylate==
<StructureSection load='6sce' size='340' side='right'caption='[[6sce]], [[Resolution|resolution]] 1.83&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6sce]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB8 Thermus thermophilus HB8] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6SCE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6SCE 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]] 1.83&#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=6sce FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6sce OCA], [https://pdbe.org/6sce PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6sce RCSB], [https://www.ebi.ac.uk/pdbsum/6sce PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6sce ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q53W14_THET8 Q53W14_THET8] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The CRISPR system provides adaptive immunity against mobile genetic elements in prokaryotes. On binding invading RNA species, Type III CRISPR systems generate cyclic oligoadenylate (cOA) signalling molecules, potentiating a powerful immune response by activating downstream effector proteins, leading to viral clearance, cell dormancy or death. Here we describe the structure and mechanism of a cOA-activated CRISPR defence DNA endonuclease, CRISPR ancillary nuclease 1 (Can1). Can1 has a unique monomeric structure with two CRISPR associated Rossman fold (CARF) domains and two DNA nuclease-like domains. The crystal structure of the enzyme has been captured in the activated state, with a cyclic tetra-adenylate (cA4) molecule bound at the core of the protein. cA4 binding reorganises the structure to license a metal-dependent DNA nuclease activity specific for nicking of supercoiled DNA. DNA nicking by Can1 is predicted to slow down viral replication kinetics by leading to the collapse of DNA replication forks.

Structure and mechanism of a Type III CRISPR defence DNA nuclease activated by cyclic oligoadenylate.,McMahon SA, Zhu W, Graham S, Rambo R, White MF, Gloster TM Nat Commun. 2020 Jan 24;11(1):500. doi: 10.1038/s41467-019-14222-x. PMID:31980625<ref>PMID:31980625</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6sce" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Thermus thermophilus HB8]]
[[Category: Gloster TM]]
[[Category: Graham S]]
[[Category: McMahon SA]]
[[Category: White MF]]
[[Category: Zhu W]]