View source for 4rq3


==Precatalytic ternary complex of Human DNA Polymerase Beta With Gapped DNA Containing an 8-oxo-7,8-dihydro-Guanine (8-oxoG) and dATP in the presence of CaCl2==
<StructureSection load='4rq3' size='340' side='right'caption='[[4rq3]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4rq3]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RQ3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RQ3 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=8OG:8-OXO-2-DEOXY-GUANOSINE-5-MONOPHOSPHATE'>8OG</scene>, <scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=DTP:2-DEOXYADENOSINE+5-TRIPHOSPHATE'>DTP</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=4rq3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rq3 OCA], [https://pdbe.org/4rq3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rq3 RCSB], [https://www.ebi.ac.uk/pdbsum/4rq3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rq3 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 ==
One common oxidative DNA lesion, 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxoG), is highly mutagenic in vivo due to its anti-conformation forming a Watson-Crick base pair with correct deoxycytidine 5'-triphosphate (dCTP) and its syn-conformation forming a Hoogsteen base pair with incorrect deoxyadenosine 5'-triphosphate (dATP). Here, we utilized time-resolved X-ray crystallography to follow 8-oxoG bypass by human DNA polymerase beta (hPolbeta). In the 12 solved structures, both Watson-Crick (anti-8-oxoG:anti-dCTP) and Hoogsteen (syn-8-oxoG:anti-dATP) base pairing were clearly visible and were maintained throughout the chemical reaction. Additionally, a third Mg2+ appeared during the process of phosphodiester bond formation and was located between the reacting alpha- and beta-phosphates of the dNTP, suggesting its role in stabilizing reaction intermediates. After phosphodiester bond formation, hPolbeta reopened its conformation, pyrophosphate was released, and the newly incorporated primer 3'-terminal nucleotide stacked, rather than base paired, with 8-oxoG. These structures provide the first real-time pictures, to our knowledge, of how a polymerase correctly and incorrectly bypasses a DNA lesion.

Viewing Human DNA Polymerase beta Faithfully and Unfaithfully Bypass an Oxidative Lesion by Time-Dependent Crystallography.,Vyas R, Reed AJ, Tokarsky EJ, Suo Z J Am Chem Soc. 2015 Apr 9. PMID:25825995<ref>PMID:25825995</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4rq3" 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: Synthetic construct]]
[[Category: Suo Z]]
[[Category: Vyas R]]