1n56: Difference between revisions

<StructureSection load='1n56' size='340' side='right'caption='[[1n56]], [[Resolution|resolution]] 2.40&Aring;' scene=''>

<table><tr><td colspan='2'>[[1n56]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharolobus_solfataricus Saccharolobus solfataricus] 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=1N56 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1N56 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]] 2.4&#8491;</td></tr>

<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3DR:1,2-DIDEOXYRIBOFURANOSE-5-PHOSPHATE'>3DR</scene>, <scene name='pdbligand=ATP:ADENOSINE-5-TRIPHOSPHATE'>ATP</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=1n56 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1n56 OCA], [https://pdbe.org/1n56 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1n56 RCSB], [https://www.ebi.ac.uk/pdbsum/1n56 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1n56 ProSAT]</span></td></tr>

[https://www.uniprot.org/uniprot/DPO4_SACS2 DPO4_SACS2] Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. It is involved in translesional synthesis.

Dpo4 from S. Solfataricus, a DinB-like Y family polymerase, efficiently replicates DNA past an abasic lesion. We have determined crystal structures of Dpo4 complexed with five different abasic site-containing DNA substrates and find that translesion synthesis is template directed with the abasic site looped out and the incoming nucleotide is opposite the base 5' to the lesion. The ensuing DNA synthesis generates a -1 frameshift when the abasic site remains extrahelical. Template realignment during primer extension is also observed, resulting in base substitutions or even +1 frameshifts. In the case of a +1 frameshift, the extra nucleotide is accommodated in the solvent-exposed minor groove. In addition, the structure of an unproductive Dpo4 ternary complex suggests that the flexible little finger domain facilitates DNA orientation and translocation during translesion synthesis.

Snapshots of replication through an abasic lesion; structural basis for base substitutions and frameshifts.,Ling H, Boudsocq F, Woodgate R, Yang W Mol Cell. 2004 Mar 12;13(5):751-62. PMID:15023344<ref>PMID:15023344</ref>

[[Category: Large Structures]]

[[Category: Saccharolobus solfataricus]]

[[Category: Synthetic construct]]

[[Category: Boudsocq F]]

[[Category: Ling H]]

[[Category: Woodgate R]]

[[Category: Yang W]]