4tus: Difference between revisions
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The | ==Human DNA polymerase beta inserting dCMPNPP opposite the 5'G of cisplatin crosslinked Gs (Pt-GG2) WITH MANGANESE IN THE ACTIVE SITE.== | ||
<StructureSection load='4tus' size='340' side='right'caption='[[4tus]], [[Resolution|resolution]] 2.42Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4tus]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TUS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4TUS 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]] 2.42Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0KX:2-DEOXY-5-O-[(R)-HYDROXY{[(R)-HYDROXY(PHOSPHONOOXY)PHOSPHORYL]AMINO}PHOSPHORYL]CYTIDINE'>0KX</scene>, <scene name='pdbligand=CPT:CISPLATIN'>CPT</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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=4tus FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4tus OCA], [https://pdbe.org/4tus PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4tus RCSB], [https://www.ebi.ac.uk/pdbsum/4tus PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4tus ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/DPOLB_HUMAN DPOLB_HUMAN] Repair polymerase that plays a key role in base-excision repair. Has 5'-deoxyribose-5-phosphate lyase (dRP lyase) activity that removes the 5' sugar phosphate and also acts as a DNA polymerase that adds one nucleotide to the 3' end of the arising single-nucleotide gap. Conducts 'gap-filling' DNA synthesis in a stepwise distributive fashion rather than in a processive fashion as for other DNA polymerases.<ref>PMID:9207062</ref> <ref>PMID:9572863</ref> <ref>PMID:11805079</ref> <ref>PMID:21362556</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Human DNA polymerase beta (polbeta) has been suggested to play a role in cisplatin resistance, especially in polbeta-overexpressing cancer cells. Polbeta has been shown to accurately, albeit slowly bypass the cisplatin-1,2-d(GpG) (Pt-GG) intramolecular cross-link in vitro. Currently, the structural basis for the inefficient Pt-GG bypass mechanism of polbeta is unknown. To gain structural insights into the mechanism, we determined two ternary structures of polbeta incorporating dCTP opposite the templating Pt-GG lesion in the presence of the active-site Mg2+ or Mn2+. The Mg2+-bound structure shows that the bulky Pt-GG adduct is accommodated in the polbeta active site without any steric hindrance. In addition, both guanines of the Pt-GG lesion form Watson-Crick base pairing with the primer terminus dC and the incoming dCTP, providing the structural basis for the accurate bypass of the Pt-GG adduct by polbeta. The Mn2+-bound structure shows that polbeta adopts a catalytically sub-optimal semi-closed conformation during the insertion of dCTP opposite the templating Pt-GG, explaining the inefficient replication across the Pt-GG lesion by polbeta. Overall, our studies provide the first structural insights into the mechanism of the potential polbeta-mediated cisplatin resistance. | |||
Structural Basis for the Inefficient Nucleotide Incorporation Opposite Cisplatin-DNA Lesion by Human DNA Polymerase beta,Koag MC, Lai L, Lee S J Biol Chem. 2014 Sep 18. pii: jbc.M114.605451. PMID:25237188<ref>PMID:25237188</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4tus" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | |||
[[Category: Large Structures]] | |||
[[Category: Koag MC]] | |||
[[Category: Lee S]] | |||