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| ==Structure of human DNA polymerase complexed with N7MG in the template base paired with incoming non-hydrolyzable CTP== | | ==Structure of human DNA polymerase complexed with N7MG in the template base paired with incoming non-hydrolyzable CTP== |
| <StructureSection load='4o5k' size='340' side='right' caption='[[4o5k]], [[Resolution|resolution]] 2.06Å' scene=''> | | <StructureSection load='4o5k' size='340' side='right'caption='[[4o5k]], [[Resolution|resolution]] 2.06Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[4o5k]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4O5K OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4O5K FirstGlance]. <br> | | <table><tr><td colspan='2'>[[4o5k]] 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=4O5K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4O5K FirstGlance]. <br> |
| </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.058Å</td></tr> |
| <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMG:2-AMINO-9-(2-DEOXY-2-FLUORO-5-O-PHOSPHONO-BETA-D-ARABINOFURANOSYL)-7-METHYL-6-OXO-6,9-DIHYDRO-1H-PURIN-7-IUM'>FMG</scene></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=FMG:2-AMINO-9-(2-DEOXY-2-FLUORO-5-O-PHOSPHONO-BETA-D-ARABINOFURANOSYL)-7-METHYL-6-OXO-6,9-DIHYDRO-1H-PURIN-7-IUM'>FMG</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> |
| <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3isb|3isb]], [[1bpx|1bpx]], [[4o5c|4o5c]], [[4o5e|4o5e]]</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=4o5k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4o5k OCA], [https://pdbe.org/4o5k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4o5k RCSB], [https://www.ebi.ac.uk/pdbsum/4o5k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4o5k ProSAT]</span></td></tr> |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4o5k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4o5k OCA], [http://pdbe.org/4o5k PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4o5k RCSB], [http://www.ebi.ac.uk/pdbsum/4o5k PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4o5k ProSAT]</span></td></tr> | |
| </table> | | </table> |
| == Function == | | == Function == |
| [[http://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> | | [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;">
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| == Publication Abstract from PubMed ==
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| N7-Methyl-2'-deoxyguanosine (m7dG) is the predominant lesion formed by methylating agents. A systematic investigation on the effect of m7dG on DNA replication has been difficult due to the chemical instability of m7dG. To gain insights into the m7dG effect, we employed a 2'-fluorine-mediated transition-state destabilzation strategy. Specifically, we determined kinetic parameters for dCTP insertion opposite a chemically stable m7dG analogue, 2'-fluoro-m7dG (Fm7dG), by human DNA polymerase beta (polbeta) and solved three X-ray structures of polbeta in complex with the templating Fm7dG paired with incoming dCTP or dTTP analogues. The kinetic studies reveal that the templating Fm7dG slows polbeta catalysis approximately 300-fold, suggesting that m7dG in genomic DNA may impede replication by some DNA polymerases. The structural analysis reveals that Fm7dG forms a canonical Watson-Crick base pair with dCTP, but metal ion coordination is suboptimal for catalysis in the polbeta-Fm7dG:dCTP complex, which partially explains the slow insertion of dCTP opposite Fm7dG by polbeta. In addition, the polbeta-Fm7dG:dTTP structure shows open protein conformations and staggered base pair conformations, indicating that N7-methylation of dG does not promote a promutagenic replication. Overall, the first systematic studies on the effect of m7dG on DNA replication reveal that polbeta catalysis across m7dG is slow, yet highly accurate.
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| Transition-state destabilization reveals how human DNA polymerase beta proceeds across the chemically unstable lesion N7-methylguanine.,Koag MC, Kou Y, Ouzon-Shubeita H, Lee S Nucleic Acids Res. 2014 Jun 25. pii: gku554. PMID:24966350<ref>PMID:24966350</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 4o5k" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
| *[[DNA polymerase|DNA polymerase]] | | *[[DNA polymerase 3D structures|DNA polymerase 3D structures]] |
| == References == | | == References == |
| <references/> | | <references/> |
| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
| [[Category: Koag, M C]] | | [[Category: Homo sapiens]] |
| [[Category: Lee, S]] | | [[Category: Large Structures]] |
| [[Category: Dna]] | | [[Category: Synthetic construct]] |
| [[Category: Dna binding]] | | [[Category: Koag MC]] |
| [[Category: Lyase-dna complex]] | | [[Category: Lee S]] |
| [[Category: Nucleotidyl transfer]]
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| [[Category: Nucleus]]
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| [[Category: Polymerase fold]]
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| [[Category: Transferase]]
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