View source for 5u34


==Crystal structure of AacC2c1-sgRNA binary complex==
<StructureSection load='5u34' size='340' side='right'caption='[[5u34]], [[Resolution|resolution]] 3.25&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5u34]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Alicyclobacillus_acidoterrestris Alicyclobacillus acidoterrestris] and [https://en.wikipedia.org/wiki/Alicyclobacillus_acidoterrestris_ATCC_49025 Alicyclobacillus acidoterrestris ATCC 49025]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5U34 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5U34 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]] 3.255&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</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=5u34 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5u34 OCA], [https://pdbe.org/5u34 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5u34 RCSB], [https://www.ebi.ac.uk/pdbsum/5u34 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5u34 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CS12B_ALIAG CS12B_ALIAG] 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). In type II CRISPR systems correct processing of pre-crRNA requires a trans-encoded small RNA (tracrRNA), endogenous ribonuclease 3 (rnc) and this protein (By similarity). The tracrRNA serves as a guide for ribonuclease 3-aided processing of pre-crRNA (By similarity). Protein-crRNA-tracrRNA endonucleolytically cleave dsDNA target complementary to the spacer; protein is inactive in the absence of crRNA homologous to the target and tracrRNA (PubMed:26593719). Recognizes a short motif in the CRISPR repeat sequences (the 5' PAM or protospacer adjacent motif, TTN in this organism) to help distinguish self versus nonself, as targets within the bacterial CRISPR locus do not have PAMs (PubMed:26593719). PAM recognition is also required for catalytic activity. Cleavage results in staggered 6-8 base 5'-overhangs 14-17 and 23-24 bases downstream of the PAM (protospacer adjacent motif) on the non-target and target strands respectively (PubMed:27984729, PubMed:27989439). Both target and non-target strand DNA are probably independently cleaved in the same active site (PubMed:27984729).[UniProtKB:A0Q5Y3]<ref>PMID:26593719</ref> <ref>PMID:27984729</ref> <ref>PMID:27989439</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
C2c1 is a newly identified guide RNA-mediated type V-B CRISPR-Cas endonuclease that site-specifically targets and cleaves both strands of target DNA. We have determined crystal structures of Alicyclobacillus acidoterrestris C2c1 (AacC2c1) bound to sgRNA as a binary complex and to target DNAs as ternary complexes, thereby capturing catalytically competent conformations of AacC2c1 with both target and non-target DNA strands independently positioned within a single RuvC catalytic pocket. Moreover, C2c1-mediated cleavage results in a staggered seven-nucleotide break of target DNA. crRNA adopts a pre-ordered five-nucleotide A-form seed sequence in the binary complex, with release of an inserted tryptophan, facilitating zippering up of 20-bp guide RNA:target DNA heteroduplex on ternary complex formation. Notably, the PAM-interacting cleft adopts a "locked" conformation on ternary complex formation. Structural comparison of C2c1 ternary complexes with their Cas9 and Cpf1 counterparts highlights the diverse mechanisms adopted by these distinct CRISPR-Cas systems, thereby broadening and enhancing their applicability as genome editing tools.

PAM-Dependent Target DNA Recognition and Cleavage by C2c1 CRISPR-Cas Endonuclease.,Yang H, Gao P, Rajashankar KR, Patel DJ Cell. 2016 Dec 15;167(7):1814-1828.e12. doi: 10.1016/j.cell.2016.11.053. PMID:27984729<ref>PMID:27984729</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5u34" style="background-color:#fffaf0;"></div>

==See Also==
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Alicyclobacillus acidoterrestris]]
[[Category: Alicyclobacillus acidoterrestris ATCC 49025]]
[[Category: Large Structures]]
[[Category: Gao P]]
[[Category: Patel DJ]]
[[Category: Rajashankar KR]]
[[Category: Yang H]]