View source for 4z6c


==Structure of human DNA polymerase beta 279NA mutant complexed with G in the template base paired with incoming non-hydrolyzable CTP==
<StructureSection load='4z6c' size='340' side='right'caption='[[4z6c]], [[Resolution|resolution]] 2.68&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4z6c]] 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=4Z6C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4Z6C 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]] 2.677&#8491;</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=MG:MAGNESIUM+ION'>MG</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=4z6c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4z6c OCA], [https://pdbe.org/4z6c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4z6c RCSB], [https://www.ebi.ac.uk/pdbsum/4z6c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4z6c 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 ==
DNA polymerases accommodate various base-pair conformations in the event of incorrect insertions. In particular, Watson-Crick-like dG:dTTP base pair has been observed at the insertion site of human DNA polymerase beta (pol beta). A potential factor contributing to the diverse conformations of base-pair mismatches is minor groove interactions. To gain insights into the effect of minor groove interactions on base-pair conformations, we generated an Asn279Ala polbeta mutant that cannot make minor groove contacts with an incoming nucleotide. We conducted structural and kinetic studies of Asn279Ala polbeta in complex with incoming dTTP and templating dG or O6-methyl-dG. The crystal structure of the Asn279Ala polbeta-G:T complex showed a wobble dG:dTTP base pair, indicating that the previously observed Watson-Crick-like dG:dTTP conformation was induced by the minor groove contact. In contrast, O6-methyl-dG, an analog of the enol tautomer of guanine, formed a Watson-Crick-like base pair with dTTP in the absence of the minor groove contact. These results suggest that the Watson-Crick-like G:T base pair at the insertion site is formed by the rare enol tautomers of G or T, whose population is increased by the minor groove hydrogen bond with Asn279. Kinetic studies showed that Asn279Ala mutation decreased dG:dTTP misincorporation rate six-fold in the presence of Mg(2+) but increased the rate three-fold in the presence of Mn(2+), highlighting the effect of minor groove interactions and metal ions on promutagenic replication by polbeta.

Insights into the effect of minor groove interactions and metal cofactors on mutagenic replication by human DNA polymerase beta.,Koag MC, Lee S Biochem J. 2018 Feb 9;475(3):571-585. doi: 10.1042/BCJ20170787. PMID:29301983<ref>PMID:29301983</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4z6c" 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 M-C]]
[[Category: Lee S]]