This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

4p2h

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 10:22, 11 August 2016

Structure of human DNA polymerase complexed with N7MG in the template opposite to incoming non-hydrolyzable TTP with manganese in the active site

Structural highlights

4p2h is a 4 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, ,
NonStd Res:
Related:	1bpx
Activity:	DNA-directed DNA polymerase, with EC number 2.7.7.7
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[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.^[1] ^[2] ^[3] ^[4]

Publication Abstract from PubMed

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.

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^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Bennett RA, Wilson DM 3rd, Wong D, Demple B. Interaction of human apurinic endonuclease and DNA polymerase beta in the base excision repair pathway. Proc Natl Acad Sci U S A. 1997 Jul 8;94(14):7166-9. PMID:9207062
↑ Matsumoto Y, Kim K, Katz DS, Feng JA. Catalytic center of DNA polymerase beta for excision of deoxyribose phosphate groups. Biochemistry. 1998 May 5;37(18):6456-64. PMID:9572863 doi:10.1021/bi9727545
↑ DeMott MS, Beyret E, Wong D, Bales BC, Hwang JT, Greenberg MM, Demple B. Covalent trapping of human DNA polymerase beta by the oxidative DNA lesion 2-deoxyribonolactone. J Biol Chem. 2002 Mar 8;277(10):7637-40. Epub 2002 Jan 22. PMID:11805079 doi:10.1074/jbc.C100577200
↑ Parsons JL, Dianova II, Khoronenkova SV, Edelmann MJ, Kessler BM, Dianov GL. USP47 is a deubiquitylating enzyme that regulates base excision repair by controlling steady-state levels of DNA polymerase beta. Mol Cell. 2011 Mar 4;41(5):609-15. doi: 10.1016/j.molcel.2011.02.016. PMID:21362556 doi:10.1016/j.molcel.2011.02.016
↑ Koag MC, Kou Y, Ouzon-Shubeita H, Lee S. Transition-state destabilization reveals how human DNA polymerase beta proceeds across the chemically unstable lesion N7-methylguanine. Nucleic Acids Res. 2014 Jun 25. pii: gku554. PMID:24966350 doi:http://dx.doi.org/10.1093/nar/gku554

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4p2h"

@@ Line 1: / Line 1: @@
 ==Structure of human DNA polymerase complexed with N7MG in the template opposite to incoming non-hydrolyzable TTP with manganese in the active site==
 <StructureSection load='4p2h' size='340' side='right' caption='[[4p2h]], [[Resolution|resolution]] 1.99&Aring;' scene=''>
@@ Line 7: / Line 8: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1bpx|1bpx]]</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/DNA-directed_DNA_polymerase DNA-directed DNA polymerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.7 2.7.7.7] </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=4p2h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4p2h OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4p2h RCSB], [http://www.ebi.ac.uk/pdbsum/4p2h PDBsum]</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=4p2h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4p2h OCA], [http://pdbe.org/4p2h PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4p2h RCSB], [http://www.ebi.ac.uk/pdbsum/4p2h PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4p2h ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 19: / Line 20: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4p2h" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[DNA polymerase|DNA polymerase]]
 == References ==
 <references/>

4p2h

From Proteopedia

Revision as of 10:22, 11 August 2016

Structure of human DNA polymerase complexed with N7MG in the template opposite to incoming non-hydrolyzable TTP with manganese in the active site

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox