View source for 8kai


==Crystal structure of SpyCas9-crRNA-tracrRNA complex bound to 17nt target DNA==
<StructureSection load='8kai' size='340' side='right'caption='[[8kai]], [[Resolution|resolution]] 3.49&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8kai]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptococcus_pyogenes_serotype_M1 Streptococcus pyogenes serotype M1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8KAI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8KAI 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]] 3.49&#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=8kai FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8kai OCA], [https://pdbe.org/8kai PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8kai RCSB], [https://www.ebi.ac.uk/pdbsum/8kai PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8kai ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CAS9_STRP1 CAS9_STRP1] 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) (Probable). In type II CRISPR systems correct processing of pre-crRNA requires a trans-encoded small RNA (tracrRNA), endogenous ribonuclease 3 (rnc) and this protein. The tracrRNA serves as a guide for ribonuclease 3-aided processing of pre-crRNA. Subsequently Cas9/crRNA/tracrRNA endonucleolytically cleaves linear or circular dsDNA target complementary to the spacer. The target strand not complementary to crRNA is first cut endonucleolytically, then trimmed by 3'-5' exonucleolytically. DNA-binding requires protein and both RNA species. Cas9 probably recognizes a short motif in the CRISPR repeat sequences (the PAM or protospacer adjacent motif) to help distinguish self versus nonself.<ref>PMID:21455174</ref> <ref>PMID:22745249</ref> 
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptococcus pyogenes serotype M1]]
[[Category: Chen J]]
[[Category: Chen Y]]
[[Category: Liu L]]