View source for 9ca0


==Human TOP3B-TDRD3 core complex in DNA pre-cleavage state==
<StructureSection load='9ca0' size='340' side='right'caption='[[9ca0]], [[Resolution|resolution]] 3.48&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9ca0]] 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=9CA0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9CA0 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.48&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=PTR:O-PHOSPHOTYROSINE'>PTR</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=9ca0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9ca0 OCA], [https://pdbe.org/9ca0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9ca0 RCSB], [https://www.ebi.ac.uk/pdbsum/9ca0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9ca0 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TOP3B_HUMAN TOP3B_HUMAN] Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-OH DNA strand. The free DNA strand than undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 3'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Possesses negatively supercoiled DNA relaxing activity.
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chen X]]
[[Category: Pommier Y]]
[[Category: Yang W]]
[[Category: Yang X]]