3px7: Difference between revisions
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3px7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3px7 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3px7 RCSB], [http://www.ebi.ac.uk/pdbsum/3px7 PDBsum]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3px7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3px7 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3px7 RCSB], [http://www.ebi.ac.uk/pdbsum/3px7 PDBsum]</span></td></tr> | ||
</table> | </table> | ||
== Function == | |||
[[http://www.uniprot.org/uniprot/C9QXS7_ECOD1 C9QXS7_ECOD1]] 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.[HAMAP-Rule:MF_00952][SAAS:SAAS00003469] | |||
==See Also== | ==See Also== | ||
Revision as of 18:51, 25 December 2014
Crystal Structure of covalent complex of topoisomerase 1A with substrateCrystal Structure of covalent complex of topoisomerase 1A with substrate
Structural highlights
Function[C9QXS7_ECOD1] 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.[HAMAP-Rule:MF_00952][SAAS:SAAS00003469] See Also |
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