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Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage

The DNA cleavage reaction of human topoisomerase IIα is critical to all of the physiological and pharmacological functions of the protein. While it has long been known that the type II enzyme requires a divalent metal ion in order to cleave DNA, the role of the cation in this process is not known. T...

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Autores principales: Deweese, Joseph E., Burgin, Alex B., Osheroff, Neil
Formato: Texto
Lenguaje:English
Publicado: Oxford University Press 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528187/
https://www.ncbi.nlm.nih.gov/pubmed/18653531
http://dx.doi.org/10.1093/nar/gkn466
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author Deweese, Joseph E.
Burgin, Alex B.
Osheroff, Neil
author_facet Deweese, Joseph E.
Burgin, Alex B.
Osheroff, Neil
author_sort Deweese, Joseph E.
collection PubMed
description The DNA cleavage reaction of human topoisomerase IIα is critical to all of the physiological and pharmacological functions of the protein. While it has long been known that the type II enzyme requires a divalent metal ion in order to cleave DNA, the role of the cation in this process is not known. To resolve this fundamental issue, the present study utilized a series of divalent metal ions with varying thiophilicities in conjunction with DNA cleavage substrates that replaced the 3′-bridging oxygen of the scissile bond with a sulfur atom (i.e. 3′-bridging phosphorothiolates). Rates and levels of DNA scission were greatly enhanced when thiophilic metal ions were included in reactions that utilized sulfur-containing substrates. Based on these results and those of reactions that employed divalent cation mixtures, we propose that topoisomerase IIα mediates DNA cleavage via a two-metal-ion mechanism. In this model, one of the metal ions makes a critical interaction with the 3′-bridging atom of the scissile phosphate. This interaction greatly accelerates rates of enzyme-mediated DNA cleavage, and most likely is needed to stabilize the leaving 3′-oxygen.
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spelling pubmed-25281872008-09-03 Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage Deweese, Joseph E. Burgin, Alex B. Osheroff, Neil Nucleic Acids Res Nucleic Acid Enzymes The DNA cleavage reaction of human topoisomerase IIα is critical to all of the physiological and pharmacological functions of the protein. While it has long been known that the type II enzyme requires a divalent metal ion in order to cleave DNA, the role of the cation in this process is not known. To resolve this fundamental issue, the present study utilized a series of divalent metal ions with varying thiophilicities in conjunction with DNA cleavage substrates that replaced the 3′-bridging oxygen of the scissile bond with a sulfur atom (i.e. 3′-bridging phosphorothiolates). Rates and levels of DNA scission were greatly enhanced when thiophilic metal ions were included in reactions that utilized sulfur-containing substrates. Based on these results and those of reactions that employed divalent cation mixtures, we propose that topoisomerase IIα mediates DNA cleavage via a two-metal-ion mechanism. In this model, one of the metal ions makes a critical interaction with the 3′-bridging atom of the scissile phosphate. This interaction greatly accelerates rates of enzyme-mediated DNA cleavage, and most likely is needed to stabilize the leaving 3′-oxygen. Oxford University Press 2008-09 2008-07-24 /pmc/articles/PMC2528187/ /pubmed/18653531 http://dx.doi.org/10.1093/nar/gkn466 Text en © 2008 The Author(s) http://creativecommons.org/licenses/by-nc/2.0/uk/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Nucleic Acid Enzymes
Deweese, Joseph E.
Burgin, Alex B.
Osheroff, Neil
Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title_full Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title_fullStr Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title_full_unstemmed Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title_short Human topoisomerase IIα uses a two-metal-ion mechanism for DNA cleavage
title_sort human topoisomerase iiα uses a two-metal-ion mechanism for dna cleavage
topic Nucleic Acid Enzymes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528187/
https://www.ncbi.nlm.nih.gov/pubmed/18653531
http://dx.doi.org/10.1093/nar/gkn466
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