View source for 5j2b


==Ternary complex crystal structure of DNA polymerase Beta with A:C mismatch at the primer terminus==
<StructureSection load='5j2b' size='340' side='right'caption='[[5j2b]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5j2b]] 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=5J2B OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5J2B 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=DUP:2-DEOXYURIDINE+5-ALPHA,BETA-IMIDO-TRIPHOSPHATE'>DUP</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=5j2b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5j2b OCA], [https://pdbe.org/5j2b PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5j2b RCSB], [https://www.ebi.ac.uk/pdbsum/5j2b PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5j2b 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> 
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== Publication Abstract from PubMed ==
High-fidelity DNA synthesis requires that polymerases display a strong preference for right nucleotide insertion. When the wrong nucleotide is inserted, the polymerase deters extension from the mismatched DNA terminus. Twenty-three crystallographic structures of DNA polymerase beta with terminal template-primer mismatches were determined as binary DNA and ternary pre-catalytic substrate complexes. These structures indicate that the mismatched termini adopt various distorted conformations that attempt to satisfy stacking and hydrogen-bonding interactions. The binary complex structures indicate an induced strain in the mismatched template nucleotide. Addition of a non-hydrolyzable incoming nucleotide stabilizes the templating nucleotide with concomitant strain in the primer terminus. Several dead-end ternary complex structures suggest that DNA synthesis might occur as the enzyme transitions from an open to a closed complex. The structures are consistent with an induced-fit mechanism where a mismatched terminus is misaligned relative to the correct incoming nucleotide to deter or delay further DNA synthesis.

Structures of DNA Polymerase Mispaired DNA Termini Transitioning to Pre-catalytic Complexes Support an Induced-Fit Fidelity Mechanism.,Batra VK, Beard WA, Pedersen LC, Wilson SH Structure. 2016 Sep 13. pii: S0969-2126(16)30238-6. doi:, 10.1016/j.str.2016.08.006. PMID:27642161<ref>PMID:27642161</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 5j2b" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Batra VK]]
[[Category: Wilson SH]]