4m9g
From Proteopedia
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4m9g]] 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=4M9G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4M9G FirstGlance]. <br> | <table><tr><td colspan='2'>[[4m9g]] 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=4M9G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4M9G FirstGlance]. <br> | ||
| - | </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=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]] 2.01Å</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=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=4m9g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4m9g OCA], [https://pdbe.org/4m9g PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4m9g RCSB], [https://www.ebi.ac.uk/pdbsum/4m9g PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4m9g ProSAT]</span></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=4m9g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4m9g OCA], [https://pdbe.org/4m9g PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4m9g RCSB], [https://www.ebi.ac.uk/pdbsum/4m9g PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4m9g ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == 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> | [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 polymerase beta (pol beta) is responsible for gap filling synthesis during repair of damaged DNA as part of the base excision repair pathway. Human pol beta mutations were recently identified in a high percentage (~30%) of tumors. Characterization of specific cancer variants is particularly useful to further the understanding of the general mechanism of pol beta while providing context to disease contribution. We showed that expression of the carcinoma variant E295K induces cellular transformation. The poor polymerase activity exhibited by the variant was hypothesized to be caused by the destabilization of proper active site assembly by the glutamate to lysine mutation. Here we show that this variant exhibits an unusual preference for binding dCTP opposite a templating adenine over the cognate dTTP. Biochemical studies indicate that the non-cognate competes with the cognate nucleotide for binding to the polymerase active site with the non-cognate incorporation a function of higher affinity and not increased activity. In the crystal structure of the variant bound to dA:dCTP, the fingers domain closes around the mismatched base pair. Nucleotide incorporation is hindered because key residues in the polymerase active site are not properly positioned for nucleotidyl transfer. In contrast to the non-cognate dCTP, neither the cognate dTTP nor its non-hydrolyzable analog induced fingers closure, as isomorphous difference Fourier maps show that the cognate nucleotides are bound to the open state of the polymerase. Comparison to published structures provides insight into the structural rearrangements within pol beta that occur during the process of nucleotide discrimination. | ||
| - | + | ==See Also== | |
| - | + | *[[DNA polymerase 3D structures|DNA polymerase 3D structures]] | |
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== References == | == References == | ||
<references/> | <references/> | ||
Current revision
DNA Polymerase Beta E295K Binary Complex
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