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4gxk
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[4gxk]] 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=4GXK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GXK FirstGlance]. <br> | <table><tr><td colspan='2'>[[4gxk]] 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=4GXK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GXK FirstGlance]. <br> | ||
| - | </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=F2A:2-DEOXY-5-O-[(S)-HYDROXY{[(S)-HYDROXY(PHOSPHONOOXY)PHOSPHORYL]METHYL}PHOSPHORYL]ADENOSINE'>F2A</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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]] 1.998Å</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=F2A:2-DEOXY-5-O-[(S)-HYDROXY{[(S)-HYDROXY(PHOSPHONOOXY)PHOSPHORYL]METHYL}PHOSPHORYL]ADENOSINE'>F2A</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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=4gxk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gxk OCA], [https://pdbe.org/4gxk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gxk RCSB], [https://www.ebi.ac.uk/pdbsum/4gxk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gxk 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=4gxk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gxk OCA], [https://pdbe.org/4gxk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gxk RCSB], [https://www.ebi.ac.uk/pdbsum/4gxk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gxk 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 == | ||
| - | A major base lesion resulting from oxidative stress is 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxoG) that has ambiguous coding potential. Error-free DNA synthesis involves 8-oxoG adopting an anti-conformation to base pair with cytosine whereas mutagenic bypass involves 8-oxoG adopting a syn-conformation to base pair with adenine. Left unrepaired the syn-8-oxoG/dAMP base pair results in a G-C to T-A transversion. During base excision repair of this mispair, DNA polymerase (pol) beta is confronted with gap filling opposite 8-oxoG. To determine how pol beta discriminates between anti- and syn-8-oxoG, we introduced a point mutation (R283K) to alter insertion specificity. Kinetic studies demonstrate that this substitution results in an increased fidelity opposite 8-oxoG. Structural studies with R283K pol beta show that the binary DNA complex has 8-oxoG in equilibrium between anti- and syn-forms. Ternary complexes with incoming dCTP resemble the wild-type enzyme, with templating anti-8-oxoG base pairing with incoming cytosine. In contrast to wild-type pol beta, the ternary complex of the R283K mutant with an incoming dATP-analogue and templating 8-oxoG resembles a G-A mismatched structure with 8-oxoG adopting an anti-conformation. These results demonstrate that the incoming nucleotide is unable to induce a syn-8-oxoG conformation without minor groove DNA polymerase interactions that influence templating (anti-/syn-equilibrium) of 8-oxoG while modulating fidelity. | ||
| - | + | ==See Also== | |
| - | + | *[[DNA polymerase 3D structures|DNA polymerase 3D structures]] | |
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== References == | == References == | ||
<references/> | <references/> | ||
Current revision
R283K DNA polymerase beta ternary complex with a templating 8OG and incoming dATP analog
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