View source for 4dzd


==Crystal structure of the CRISPR-associated protein Cas6e from Escherichia coli str. K-12==
<StructureSection load='4dzd' size='340' side='right'caption='[[4dzd]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4dzd]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4DZD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4DZD 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]] 1.999&#8491;</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=4dzd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4dzd OCA], [https://pdbe.org/4dzd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4dzd RCSB], [https://www.ebi.ac.uk/pdbsum/4dzd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4dzd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CAS6_ECOLI CAS6_ECOLI] 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 sequences complementary to antecedent mobile elements and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA).<ref>PMID:18703739</ref> <ref>PMID:21219465</ref> <ref>PMID:21255106</ref> <ref>PMID:21460843</ref> <ref>PMID:21699496</ref>   CasE is required to process the pre-crRNA into single repeat-spacer units, with an 8-nt 5'-repeat DNA tag that may help other proteins recognize the crRNA. This subunit alone will cleave pre-crRNA, as will CasCDE or CasCE; cleavage does not require divalent metals or ATP. CasCDE alone is also able to form R-loops. Partially inhibits the cleavage of Holliday junctions by YgbT (Cas1). Yields a 5'-hydroxy group and a 2',3'-cyclic phosphate terminus.<ref>PMID:18703739</ref> <ref>PMID:21219465</ref> <ref>PMID:21255106</ref> <ref>PMID:21460843</ref> <ref>PMID:21699496</ref>   A component of Cascade, which participates in CRISPR interference, the third stage of CRISPR immunity. Cascade binds both crRNA and in a sequence-specific manner negatively supercoiled dsDNA target. This leads to the formation of an R-loop in which the crRNA binds the target DNA, displacing the noncomplementary strand. Cas3 is recruited to Cascade, nicks target DNA and then unwinds and cleaves the target, leading to DNA degradation and invader neutralization.<ref>PMID:18703739</ref> <ref>PMID:21219465</ref> <ref>PMID:21255106</ref> <ref>PMID:21460843</ref> <ref>PMID:21699496</ref> 

==See Also==
*[[CRISPR type I-E (Cascade)|CRISPR type I-E (Cascade)]]
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Gong W]]
[[Category: Huang G]]
[[Category: Wang Y]]
[[Category: Wei J]]