View source for 1cz0


==INTRON ENCODED HOMING ENDONUCLEASE I-PPOI/DNA COMPLEX LACKING CATALYTIC METAL ION==
<StructureSection load='1cz0' size='340' side='right'caption='[[1cz0]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1cz0]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Physarum_polycephalum Physarum polycephalum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CZ0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CZ0 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</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=1cz0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cz0 OCA], [https://pdbe.org/1cz0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cz0 RCSB], [https://www.ebi.ac.uk/pdbsum/1cz0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cz0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PPO1_PHYPO PPO1_PHYPO] Mediates the homing of a group I intron in the ribosomal DNA. Makes a four-base staggered cut in its ribosomal DNA target sequence.
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== Publication Abstract from PubMed ==
A novel mechanism of DNA endonucleolytic cleavage has been visualized for the homing endonuclease I-PpoI by trapping the uncleaved enzyme-substrate complex and comparing it to the previously visualized product complex. This enzyme employs a unique single metal mechanism. A magnesium ion is coordinated by an asparagine residue and two DNA oxygen atoms and stabilizes the phosphoanion transition state and the 3'oxygen leaving group. A hydrolytic water molecule is activated by a histidine residue for an in-line attack on the scissile phosphate. A strained enzyme-substrate-metal complex is formed before cleavage, then relaxed during the reaction.

A novel endonuclease mechanism directly visualized for I-PpoI.,Galburt EA, Chevalier B, Tang W, Jurica MS, Flick KE, Monnat RJ Jr, Stoddard BL Nat Struct Biol. 1999 Dec;6(12):1096-9. PMID:10581547<ref>PMID:10581547</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 1cz0" style="background-color:#fffaf0;"></div>

==See Also==
*[[Endonuclease 3D structures|Endonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Physarum polycephalum]]
[[Category: Chevalier B]]
[[Category: Flick KE]]
[[Category: Galburt EA]]
[[Category: Jurica MS]]
[[Category: Stoddard BL]]