View source for 4qts


==Crystal structure of Csm3-Csm4 subcomplex in the type III-A CRISPR-Cas interference complex==
<StructureSection load='4qts' size='340' side='right'caption='[[4qts]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4qts]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii_DSM_2661 Methanocaldococcus jannaschii DSM 2661]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QTS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4QTS 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]] 3.105&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</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=4qts FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qts OCA], [https://pdbe.org/4qts PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4qts RCSB], [https://www.ebi.ac.uk/pdbsum/4qts PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4qts ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CSM4_METJA CSM4_METJA] 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).
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== Publication Abstract from PubMed ==
Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci play a pivotal role in the prokaryotic host defense system against invading genetic materials. The CRISPR loci are transcribed to produce CRISPR RNAs (crRNAs), which form interference complexes with CRISPR-associated (Cas) proteins to target the invading nucleic acid for degradation. The interference complex of the type III-A CRISPR-Cas system is composed of five Cas proteins (Csm1-Csm5) and a crRNA, and targets invading DNA. Here, we show that the Csm1, Csm3, and Csm4 proteins from Methanocaldococcus jannaschii form a stable subcomplex. We also report the crystal structure of the M. jannaschii Csm3-Csm4 subcomplex at 3.1A resolution. The complex structure revealed the presence of a basic concave surface around their interface, suggesting the RNA and/or DNA binding ability of the complex. A gel retardation analysis showed that the Csm3-Csm4 complex binds single-stranded RNA in a non-sequence-specific manner. Csm4 structurally resembles Cmr3, a component of the type III-B CRISPR-Cas interference complex. Based on bioinformatics, we constructed a model structure of the Csm1-Csm4-Csm3 ternary complex, which provides insights into its role in the Csm interference complex.

Crystal Structure of the Csm3-Csm4 Subcomplex in the Type III-A CRISPR-Cas Interference Complex.,Numata T, Inanaga H, Sato C, Osawa T J Mol Biol. 2014 Oct 30. pii: S0022-2836(14)00564-6. doi:, 10.1016/j.jmb.2014.09.029. PMID:25451598<ref>PMID:25451598</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 4qts" style="background-color:#fffaf0;"></div>

==See Also==
*[[CRISPR subtype III-A (Csm complex)|CRISPR subtype III-A (Csm complex)]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Methanocaldococcus jannaschii DSM 2661]]
[[Category: Inanaga H]]
[[Category: Numata T]]
[[Category: Osawa T]]