View source for 1bpz


==HUMAN DNA POLYMERASE BETA COMPLEXED WITH NICKED DNA==
<StructureSection load='1bpz' size='340' side='right'caption='[[1bpz]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1bpz]] 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=1BPZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BPZ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=1bpz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bpz OCA], [https://pdbe.org/1bpz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bpz RCSB], [https://www.ebi.ac.uk/pdbsum/1bpz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bpz 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/bp/1bpz_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=1bpz ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
DNA polymerase beta (pol beta) fills single nucleotide (nt) gaps in DNA produced by the base excision repair pathway of mammalian cells. Crystal structures have been determined representing intermediates in the 1 nt gap-filling reaction of pol beta: the binary complex with a gapped DNA substrate (2.4 A resolution), the ternary complex including ddCTP (2.2 A), and the binary product complex containing only nicked DNA (2.6 A). Upon binding ddCTP to the binary gap complex, the thumb subdomain rotates into the closed conformation to contact the otherwise solvent-exposed ddCTP-template base pair. Thumb movement triggers further conformational changes which poise catalytic residue Asp192, dNTP, and template for nucleotidyl transfer, effectively assembling the active site. In the product nicked DNA complex, the thumb returns to the open conformation as in the gapped binary DNA complex, facilitating dissociation of the product. These findings suggest that pol beta may enhance fidelity by an induced fit mechanism in which correct base pairing between template and incoming dNTP induces alignment of catalytic groups for catalysis (via thumb closure), but incorrect base pairing will not. The structures also reveal that pol beta binds both gapped and nicked DNA with a 90 degrees kink occurring precisely at the 5'-phosphodiester linkage of the templating residue. If the DNA were not kinked in this way, contact between the thumb and dNTP-template base pair, presumably important for the checking mechanism, would be impossible, especially when the gap is but a single nucleotide. Such a 90 degrees kink may be a mechanistic feature employed by any polymerase involved in filling gaps to completion.

Crystal structures of human DNA polymerase beta complexed with gapped and nicked DNA: evidence for an induced fit mechanism.,Sawaya MR, Prasad R, Wilson SH, Kraut J, Pelletier H Biochemistry. 1997 Sep 16;36(37):11205-15. PMID:9287163<ref>PMID:9287163</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1bpz" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Kraut J]]
[[Category: Pelletier H]]
[[Category: Prasad R]]
[[Category: Sawaya MR]]
[[Category: Wilson SH]]