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[[Image:7icf.gif|left|200px]]


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==DNA POLYMERASE BETA (POL B) (E.C.2.7.7.7) COMPLEXED WITH SIX BASE PAIRS OF DNA; SOAKED IN THE PRESENCE OF CDCL2 (0.1 MILLIMOLAR) (FOUR-DAY SOAK)==
The line below this paragraph, containing "STRUCTURE_7icf", creates the "Structure Box" on the page.
<StructureSection load='7icf' size='340' side='right'caption='[[7icf]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
You may change the PDB parameter (which sets the PDB file loaded into the applet)
== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[7icf]] is a 3 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=7ICF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ICF FirstGlance]. <br>
or leave the SCENE parameter empty for the default display.
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.1&#8491;</td></tr>
-->
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CD:CADMIUM+ION'>CD</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>
{{STRUCTURE_7icf|  PDB=7icf  |  SCENE=  }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7icf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7icf OCA], [https://pdbe.org/7icf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7icf RCSB], [https://www.ebi.ac.uk/pdbsum/7icf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7icf 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>
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ic/7icf_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=7icf ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
When crystals of human DNA polymerase beta (pol beta) complexed with DNA [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., &amp; Kraut, J. (1996) Biochemistry 35, 12742-12761] are soaked in the presence of dATP and Mn2+, X-ray structural analysis shows that nucleotidyl transfer to the primer 3'-OH takes place directly in the crystals, even though the DNA is blunt-ended at the active site. Under similar crystal-soaking conditions, there is no evidence for a reaction when Mn2+ is replaced by Mg2+, which is thought to be the divalent metal ion utilized by most polymerases in vivo. These results suggest that one way Mn2+ may manifest its mutagenic effect on polymerases is by promoting greater reactivity than Mg2+ at the catalytic site, thereby allowing the nucleotidyl transfer reaction to take place with little or no regard to instructions from a template. Non-template-directed nucleotidyl transfer is also observed when pol beta-DNA cocrystals are soaked in the presence of dATP and Zn2+, but the reaction products differ in that the sugar moiety of the incorporated nucleotide appears distorted or otherwise cleaved, in agreement with reports that Zn2+ may act as a polymerase inhibitor rather than as a mutagen [Sirover, M. A., &amp; Loeb, L. A. (1976) Science 194, 1434-1436]. Although no reaction is observed when crystals are soaked in the presence of dATP and other metal ions such as Ca2+, Co2+, Cr3+, or Ni2+, X-ray structural analyses show that these metal ions coordinate the triphosphate moiety of the nucleotide in a manner that differs from that observed with Mg2+. In addition, all metal ions tested, with the exception of Mg2+, promote a change in the side-chain position of aspartic acid 192, which is one of three highly conserved active-site carboxylate residues. Soaking experiments with nucleotides other than dATP (namely, dCTP, dGTP, dTTP, ATP, ddATP, ddCTP, AZT-TP, and dATP alpha S) reveal a non-base-specific binding site on pol beta for the triphosphate and sugar moieties of a nucleotide, suggesting a possible mechanism for nucleotide selectivity whereby triphosphate-sugar binding precedes a check for correct base pairing with the template.


'''DNA POLYMERASE BETA (POL B) (E.C.2.7.7.7) COMPLEXED WITH SIX BASE PAIRS OF DNA; SOAKED IN THE PRESENCE OF CDCL2 (0.1 MILLIMOLAR) (FOUR-DAY SOAK)'''
A structural basis for metal ion mutagenicity and nucleotide selectivity in human DNA polymerase beta.,Pelletier H, Sawaya MR, Wolfle W, Wilson SH, Kraut J Biochemistry. 1996 Oct 1;35(39):12762-77. PMID:8841119<ref>PMID:8841119</ref>


From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7icf" style="background-color:#fffaf0;"></div>


==Overview==
==See Also==
X-ray crystallographic studies have shown that DNA binding by human polymerase beta (pol beta) occurs primarily through two structurally and sequentially homologous helix-hairpin-helix (HhH) motifs, one in the fingers subdomain and the other in the 8-kDa domain [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., &amp; Kraut, J. (1996a) Biochemistry 35, 12742-12761]. In that DNA binding by each HhH motif is facilitated by a metal ion, we set out to determine the identity of the metal ion that most likely binds to the HhH motif in vivo. Crystal soaking experiments were performed on human pol beta-DNA cocrystals with Mg2+, Ca2+, Na+, and K+, the four most prevalent metal ions in the cell, and in each case a data set was collected and the resulting structure was refined. Under the conditions tested, the HhH motifs of pol beta have an affinity for these biologically prevalent metal ions in the order Mg2+ &lt; Ca2+ &lt; Na+ &lt; K+, with K+ displaying the strongest binding. Crystals soaked in the presence of Tl+, a commonly used spectroscopic probe for K+, were too X-ray-sensitive to establish the binding behavior of Tl+, but soaking experiments with Ba2+ and Cs+ resulted in relatively stable crystals that gave evidence of metal ion binding in both HhH motifs, confirming that larger monovalent and divalent metal ions are capable of binding to the HhH metal sites. Although Mn2+, which has been categorized as a potent polymerase mutagen, binds to the HhH motifs with a greater affinity than Mg2+, Mn2+ does not bind to the HhH motifs in the presence of equimolar concentrations of Na+. These results suggest that in vivo, where Mn2+ is present only in trace amounts, Mn2+ probably does not have a large effect on DNA binding and may instead manifest a mutagenic effect on pol beta primarily by distorting nucleotide binding or by directly affecting the catalytic step [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., &amp; Kraut, J. (1996b) Biochemistry 35, 12762-12777]. Crystal soaking experiments with 31-kDa apoenzyme crystals show that, in the absence of DNA, the HhH motif in the fingers subdomain binds metal ions with either much lower occupancy or not at all, indicating that metal ion binding is dependent on the presence of the DNA substrate.
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
 
== References ==
==About this Structure==
<references/>
7ICF is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7ICF OCA].
__TOC__
 
</StructureSection>
==Reference==
Characterization of the metal ion binding helix-hairpin-helix motifs in human DNA polymerase beta by X-ray structural analysis., Pelletier H, Sawaya MR, Biochemistry. 1996 Oct 1;35(39):12778-87. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8841120 8841120]
[[Category: Homo sapiens]]
[[Category: Homo sapiens]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Pelletier, H.]]
[[Category: Pelletier H]]
[[Category: Sawaya, M R.]]
[[Category: Sawaya MR]]
[[Category: Dna repair]]
[[Category: Dna replication]]
[[Category: Dna-directed dna polymerase]]
[[Category: Nucleotidyltransferase]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 22:45:27 2008''

Latest revision as of 14:07, 2 August 2023

DNA POLYMERASE BETA (POL B) (E.C.2.7.7.7) COMPLEXED WITH SIX BASE PAIRS OF DNA; SOAKED IN THE PRESENCE OF CDCL2 (0.1 MILLIMOLAR) (FOUR-DAY SOAK)DNA POLYMERASE BETA (POL B) (E.C.2.7.7.7) COMPLEXED WITH SIX BASE PAIRS OF DNA; SOAKED IN THE PRESENCE OF CDCL2 (0.1 MILLIMOLAR) (FOUR-DAY SOAK)

Structural highlights

7icf is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 3.1Å
Ligands:,
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]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

When crystals of human DNA polymerase beta (pol beta) complexed with DNA [Pelletier, H., Sawaya, M. R., Wolfle, W., Wilson, S. H., & Kraut, J. (1996) Biochemistry 35, 12742-12761] are soaked in the presence of dATP and Mn2+, X-ray structural analysis shows that nucleotidyl transfer to the primer 3'-OH takes place directly in the crystals, even though the DNA is blunt-ended at the active site. Under similar crystal-soaking conditions, there is no evidence for a reaction when Mn2+ is replaced by Mg2+, which is thought to be the divalent metal ion utilized by most polymerases in vivo. These results suggest that one way Mn2+ may manifest its mutagenic effect on polymerases is by promoting greater reactivity than Mg2+ at the catalytic site, thereby allowing the nucleotidyl transfer reaction to take place with little or no regard to instructions from a template. Non-template-directed nucleotidyl transfer is also observed when pol beta-DNA cocrystals are soaked in the presence of dATP and Zn2+, but the reaction products differ in that the sugar moiety of the incorporated nucleotide appears distorted or otherwise cleaved, in agreement with reports that Zn2+ may act as a polymerase inhibitor rather than as a mutagen [Sirover, M. A., & Loeb, L. A. (1976) Science 194, 1434-1436]. Although no reaction is observed when crystals are soaked in the presence of dATP and other metal ions such as Ca2+, Co2+, Cr3+, or Ni2+, X-ray structural analyses show that these metal ions coordinate the triphosphate moiety of the nucleotide in a manner that differs from that observed with Mg2+. In addition, all metal ions tested, with the exception of Mg2+, promote a change in the side-chain position of aspartic acid 192, which is one of three highly conserved active-site carboxylate residues. Soaking experiments with nucleotides other than dATP (namely, dCTP, dGTP, dTTP, ATP, ddATP, ddCTP, AZT-TP, and dATP alpha S) reveal a non-base-specific binding site on pol beta for the triphosphate and sugar moieties of a nucleotide, suggesting a possible mechanism for nucleotide selectivity whereby triphosphate-sugar binding precedes a check for correct base pairing with the template.

A structural basis for metal ion mutagenicity and nucleotide selectivity in human DNA polymerase beta.,Pelletier H, Sawaya MR, Wolfle W, Wilson SH, Kraut J Biochemistry. 1996 Oct 1;35(39):12762-77. PMID:8841119[5]

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

See Also

References

  1. ↑ 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
  2. ↑ 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
  3. ↑ 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
  4. ↑ 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
  5. ↑ Pelletier H, Sawaya MR, Wolfle W, Wilson SH, Kraut J. A structural basis for metal ion mutagenicity and nucleotide selectivity in human DNA polymerase beta. Biochemistry. 1996 Oct 1;35(39):12762-77. PMID:8841119 doi:http://dx.doi.org/10.1021/bi9529566

7icf, resolution 3.10Å

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