View source for 3ung


==Structure of the Cmr2 subunit of the CRISPR RNA silencing complex==
<StructureSection load='3ung' size='340' side='right'caption='[[3ung]], [[Resolution|resolution]] 2.31&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ung]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pyrococcus_furiosus_DSM_3638 Pyrococcus furiosus DSM 3638]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3UNG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3UNG 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]] 2.31&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <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=3ung FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ung OCA], [https://pdbe.org/3ung PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ung RCSB], [https://www.ebi.ac.uk/pdbsum/3ung PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ung ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CMR2_PYRFU CMR2_PYRFU] 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), formerly called psiRNA (prokaryotic silencing) in this organism. Part of the Cmr ribonucleoprotein complex which has divalent cation-dependent endoribonuclease activity specific for ssRNA complementary to the crRNA, generating 5' hydroxy- and 3' phosphate or 2'-3' cyclic phosphate termini. It is not known which subunit has endoribonuclease activity. Cmr complex does not cleave ssDNA complementary to the crRNA. Cleavage of invading RNA is guided by the crRNA; substrate cleavage occurs a fixed distance (14 nt) from the 3' end of the crRNA. In vitro reconstitution shows Cmr1-2 and Cmr5 are not necessary for cleavage. Probably not the subunit that cleaves pre-crRNA, as mutation of numerous metal-binding residues have no effect on cleavage by assembled complex.<ref>PMID:19945378</ref> 

==See Also==
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pyrococcus furiosus DSM 3638]]
[[Category: Cocozaki AI]]
[[Category: Hale CR]]
[[Category: Li H]]
[[Category: Ramia NF]]
[[Category: Shao Y]]
[[Category: Terns MP]]
[[Category: Terns RM]]