View source for 3pwt


==Crystal structure of mutant E.coli topoisomerase IA==
<StructureSection load='3pwt' size='340' side='right'caption='[[3pwt]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3pwt]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PWT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3PWT FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ecl|1ecl]], [[1cy0|1cy0]], [[1cy2|1cy2]], [[1cy4|1cy4]], [[1cy6|1cy6]], [[1cy7|1cy7]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">topA, supX, b1274, JW1266 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 ECOLI])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/DNA_topoisomerase DNA topoisomerase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.99.1.2 5.99.1.2] </span></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=3pwt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3pwt OCA], [https://pdbe.org/3pwt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3pwt RCSB], [https://www.ebi.ac.uk/pdbsum/3pwt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3pwt ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/TOP1_ECOLI TOP1_ECOLI]] Releases the supercoiling and torsional tension of DNA, which is 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 then 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.<ref>PMID:9497321</ref> <ref>PMID:10681504</ref> <ref>PMID:21482796</ref>  

==See Also==
*[[Topoisomerase 3D structures|Topoisomerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: DNA topoisomerase]]
[[Category: Ecoli]]
[[Category: Large Structures]]
[[Category: Bokun, C]]
[[Category: Tse-Dinh, Y C]]
[[Category: Zhang, Z]]
[[Category: Dna relaxation]]
[[Category: Isomerase]]
[[Category: Topoisomerase]]