View source for 6as3


==Structure of a phage anti-CRISPR protein==
<StructureSection load='6as3' size='340' side='right'caption='[[6as3]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6as3]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_phage_JBD5 Pseudomonas phage JBD5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6AS3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6AS3 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&#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=6as3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6as3 OCA], [https://pdbe.org/6as3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6as3 RCSB], [https://www.ebi.ac.uk/pdbsum/6as3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6as3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/L7P7L6_9CAUD L7P7L6_9CAUD] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
CRISPR (clustered regularly interspaced short palindromic repeat)-Cas adaptive immune systems are prevalent defense mechanisms in bacteria and archaea. They provide sequence-specific detection and neutralization of foreign nucleic acids such as bacteriophages and plasmids. One mechanism by which phages and other mobile genetic elements are able to overcome the CRISPR-Cas system is through the expression of anti-CRISPR proteins. Over 20 different families of anti-CRISPR proteins have been described, each of which inhibits a particular type of CRISPR-Cas system. In this work, we determined the structure of type I-E anti-CRISPR protein AcrE1 by X-ray crystallography. We show that AcrE1 binds to the CRISPR-associated helicase/nuclease Cas3 and that the C-terminal region of the anti-CRISPR protein is important for its inhibitory activity. We further show that AcrE1 can convert the endogenous type I-E CRISPR system into a programmable transcriptional repressor.IMPORTANCE The CRISPR-Cas immune system provides bacteria with resistance to invasion by potentially harmful viruses, plasmids, and other foreign mobile genetic elements. This study presents the first structural and mechanistic insight into a phage-encoded protein that inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa The interaction of this anti-CRISPR protein with the CRISPR-associated helicase/nuclease proteins Cas3 shuts down the CRISPR-Cas system and protects phages carrying this gene from destruction. This interaction also allows the repurposing of the endogenous type I-E CRISPR system into a programmable transcriptional repressor, providing a new biotechnological tool for genetic studies of bacteria encoding this type I-E CRISPR-Cas system.

Disabling a Type I-E CRISPR-Cas Nuclease with a Bacteriophage-Encoded Anti-CRISPR Protein.,Pawluk A, Shah M, Mejdani M, Calmettes C, Moraes TF, Davidson AR, Maxwell KL MBio. 2017 Dec 12;8(6). pii: mBio.01751-17. doi: 10.1128/mBio.01751-17. PMID:29233895<ref>PMID:29233895</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6as3" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas phage JBD5]]
[[Category: Calmettes C]]
[[Category: Davidson AR]]
[[Category: Maxwell KL]]
[[Category: Mejdani M]]
[[Category: Moraes TF]]
[[Category: Pawluk A]]
[[Category: Shah M]]