View source for 4gp7


==Polynucleotide kinase==
<StructureSection load='4gp7' size='340' side='right'caption='[[4gp7]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4gp7]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Acetivibrio_thermocellus_ATCC_27405 Acetivibrio thermocellus ATCC 27405]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GP7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GP7 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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4gp7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gp7 OCA], [https://pdbe.org/4gp7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gp7 RCSB], [https://www.ebi.ac.uk/pdbsum/4gp7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gp7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A3DJ38_ACET2 A3DJ38_ACET2] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Pnkp is the end-healing and end-sealing component of an RNA repair system present in diverse bacteria from many phyla. Pnkp is composed of three catalytic modules: an N-terminal polynucleotide 5'-kinase, a central 2',3' phosphatase, and a C-terminal ligase. Here we report the crystal structure of the kinase domain of Clostridium thermocellum Pnkp bound to ATP*Mg(2+) (substrate complex) and ADP*Mg(2+) (product complex). The protein consists of a core P-loop phosphotransferase fold embellished by a distinctive homodimerization module composed of secondary structure elements derived from the N and C termini of the kinase domain. ATP is bound within a crescent-shaped groove formed by the P-loop ((15)GSSGSGKST(23)) and an overlying helix-loop-helix "lid." The alpha and beta phosphates are engaged by a network of hydrogen bonds from Thr23 and the P-loop main-chain amides; the gamma phosphate is anchored by the lid residues Arg120 and Arg123. The P-loop lysine (Lys21) and the catalytic Mg(2+) bridge the ATP beta and gamma phosphates. The P-loop serine (Ser22) is the sole enzymic constituent of the octahedral metal coordination complex. Structure-guided mutational analysis underscored the essential contributions of Lys21 and Ser22 in the ATP donor site and Asp38 and Arg41 in the phosphoacceptor site. Our studies suggest a catalytic mechanism whereby Asp38 (as general base) activates the polynucleotide 5'-OH for its nucleophilic attack on the gamma phosphorus and Lys21 and Mg(2+) stabilize the transition state.

Structure and mechanism of the polynucleotide kinase component of the bacterial Pnkp-Hen1 RNA repair system.,Wang LK, Das U, Smith P, Shuman S RNA. 2012 Nov 1. PMID:23118415<ref>PMID:23118415</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4gp7" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Acetivibrio thermocellus ATCC 27405]]
[[Category: Large Structures]]
[[Category: Das U]]
[[Category: Shuman S]]
[[Category: Smith P]]
[[Category: Wang LK]]