OCA at 14:38, 18 October 2023

OCA — Wed, 18 Oct 2023 14:38:32 GMT

←Older revision		Revision as of 14:38, 18 October 2023
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-	====	+	==Crystal structure of CRISPR-associated transcription factor Csa3 complexed with cA4==
-	<StructureSection load='6wxq' size='340' side='right'caption='[[6wxq]]' scene=''>	+	<StructureSection load='6wxq' size='340' side='right'caption='[[6wxq]], [[Resolution\|resolution]] 2.05Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id= OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol= FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[6wxq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus Saccharolobus solfataricus] 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=6WXQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6WXQ FirstGlance]. <br>
-	</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=6wxq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6wxq OCA], [https://pdbe.org/6wxq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6wxq RCSB], [https://www.ebi.ac.uk/pdbsum/6wxq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6wxq ProSAT]</span></td></tr>	+	</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models\|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution\|Resolution]] 2.05Å</td></tr>
		+	<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=6wxq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6wxq OCA], [https://pdbe.org/6wxq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6wxq RCSB], [https://www.ebi.ac.uk/pdbsum/6wxq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6wxq ProSAT]</span></td></tr>
	</table>		</table>
		+	== Function ==
		+	[https://www.uniprot.org/uniprot/CSA3_SACS2 CSA3_SACS2] CRISPR (clustered regularly interspaced short palindromic repeat) is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA) (By similarity).
		+	<div style="background-color:#fffaf0;">
		+	== Publication Abstract from PubMed ==
		+	RNA interference by type III CRISPR systems results in the synthesis of cyclic oligoadenylate (cOA) second messengers, which are known to bind and regulate various CARF domain-containing nuclease receptors. The CARF domain-containing Csa3 family of transcriptional factors associated with the DNA-targeting type I CRISPR systems regulate expression of various CRISPR and DNA repair genes in many prokaryotes. In this study, we extend the known receptor repertoire of cOA messengers to include transcriptional factors by demonstrating specific binding of cyclic tetra-adenylate (cA4) to Saccharolobus solfataricus Csa3 (Csa3(Sso)). Our 2.0-A resolution X-ray crystal structure of cA4-bound full-length Csa3(Sso) reveals the binding of its CARF domain to an elongated conformation of cA4. Using cA4 binding affinity analyses of Csa3(Sso) mutants targeting the observed Csa3(Sso)*cA4 structural interface, we identified a Csa3-specific cA4 binding motif distinct from a more widely conserved cOA-binding CARF motif. Using a rational surface engineering approach, we increased the cA4 binding affinity of Csa3(Sso) up to approximately 145-fold over the wildtype, which has potential applications for future second messenger-driven CRISPR gene expression and editing systems. Our in-solution Csa3(Sso) structural analysis identified cA4-induced allosteric and asymmetric conformational rearrangement of its C-terminal winged helix-turn-helix effector domains, which could potentially be incompatible to DNA binding. However, specific in vitro binding of the purified Csa3(Sso) to its putative promoter (P(Cas4a)) was found to be cA4 independent, suggesting a complex mode of Csa3(Sso) regulation. Overall, our results support cA4-and Csa3-mediated cross talk between type III and type I CRISPR systems.
		+
		+	Structural basis of cyclic oligoadenylate binding to the transcription factor Csa3 outlines cross talk between type III and type I CRISPR systems.,Xia P, Dutta A, Gupta K, Batish M, Parashar V J Biol Chem. 2022 Feb;298(2):101591. doi: 10.1016/j.jbc.2022.101591. Epub 2022 , Jan 14. PMID:35038453<ref>PMID:35038453</ref>
		+
		+	From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
		+	</div>
		+	<div class="pdbe-citations 6wxq" style="background-color:#fffaf0;"></div>
		+	== References ==
		+	<references/>
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
	[[Category: Large Structures]]		[[Category: Large Structures]]
-	[[Category: ~~Z-disk~~]]	+	[[Category: Saccharolobus solfataricus]]
		+	[[Category: Synthetic construct]]
		+	[[Category: Dutta A]]
		+	[[Category: Parashar V]]
		+	[[Category: Xia P]]

OCA at 13:33, 17 November 2021

OCA — Wed, 17 Nov 2021 13:33:54 GMT

←Older revision		Revision as of 13:33, 17 November 2021
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-	'''Unreleased structure'''

-	~~The entry~~ 6wxq ~~is ON HOLD until Nov 17 2022~~	+	====
-		+	<StructureSection load='6wxq' size='340' side='right'caption='[[6wxq]]' scene=''>
-	~~Authors~~:	+	== Structural highlights ==
-		+	<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id= OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol= FirstGlance]. <br>
-	~~Description~~:	+	</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=6wxq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6wxq OCA], [https://pdbe.org/6wxq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6wxq RCSB], [https://www.ebi.ac.uk/pdbsum/6wxq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6wxq ProSAT]</span></td></tr>
-	[[Category: ~~Unreleased~~ Structures]]	+	</table>
		+	__TOC__
		+	</StructureSection>
		+	[[Category: Large Structures]]
		+	[[Category: Z-disk]]

OCA at 07:12, 5 May 2021

OCA — Wed, 05 May 2021 07:12:42 GMT

←Older revision		Revision as of 07:12, 5 May 2021
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	'''Unreleased structure'''		'''Unreleased structure'''

-	The entry 6wxq is ON HOLD until ~~May 11~~ 2022	+	The entry 6wxq is ON HOLD until Nov 17 2022

	Authors:		Authors:

OCA at 04:54, 10 June 2020

OCA — Wed, 10 Jun 2020 04:54:07 GMT

←Older revision		Revision as of 04:54, 10 June 2020
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	'''Unreleased structure'''		'''Unreleased structure'''

-	The entry 6wxq is ON HOLD	+	The entry 6wxq is ON HOLD until May 11 2022

	Authors:		Authors:

OCA: Protected "6wxq" [edit=sysop:move=sysop]

OCA — Wed, 20 May 2020 04:20:15 GMT

Protected "6wxq" [edit=sysop:move=sysop]

←Older revision

Revision as of 04:20, 20 May 2020

OCA: New page: '''Unreleased structure''' The entry 6wxq is ON HOLD Authors: Description: Category: Unreleased Structures

OCA — Wed, 20 May 2020 04:20:13 GMT

New page: '''Unreleased structure''' The entry 6wxq is ON HOLD Authors: Description: Category: Unreleased Structures

New page