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Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies
Topoisomerase V (Topo-V) is the only member of a novel topoisomerase subtype. Topo-V is unique because it is a bifunctional enzyme carrying both topoisomerase and DNA repair lyase activities within the same protein. Previous studies had shown that the topoisomerase domain spans the N-terminus of the...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Oxford University Press
2013
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592480/ https://www.ncbi.nlm.nih.gov/pubmed/23125368 http://dx.doi.org/10.1093/nar/gks1017 |
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author | Rajan, Rakhi Prasad, Rajendra Taneja, Bhupesh Wilson, Samuel H. Mondragón, Alfonso |
author_facet | Rajan, Rakhi Prasad, Rajendra Taneja, Bhupesh Wilson, Samuel H. Mondragón, Alfonso |
author_sort | Rajan, Rakhi |
collection | PubMed |
description | Topoisomerase V (Topo-V) is the only member of a novel topoisomerase subtype. Topo-V is unique because it is a bifunctional enzyme carrying both topoisomerase and DNA repair lyase activities within the same protein. Previous studies had shown that the topoisomerase domain spans the N-terminus of the protein and is followed by 12 tandem helix–hairpin–helix [(HhH)(2)] domains. There are at least two DNA repair lyase active sites for apurinic/apyrimidinic (AP) site processing, one within the N-terminal region and the second within the C-terminal domain of Topo-V, but their exact locations and characteristics are unknown. In the present study, the N-terminal 78-kDa fragment of Topo-V (Topo-78), containing the topoisomerase domain and one of the lyase DNA repair domains, was characterized by structural and biochemical studies. The results show that an N-terminal 69-kDa fragment is the minimal fragment with both topoisomerase and AP lyase activities. The lyase active site of Topo-78 is at the junction of the fifth and sixth (HhH)(2) domains. From the biochemical and structural data, it appears that Lys571 is the most probable nucleophile responsible for the lyase activity. Our experiments also suggest that Topo-V most likely acts as a Class I AP endonuclease in vivo. |
format | Online Article Text |
id | pubmed-3592480 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-35924802013-03-08 Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies Rajan, Rakhi Prasad, Rajendra Taneja, Bhupesh Wilson, Samuel H. Mondragón, Alfonso Nucleic Acids Res Structural Biology Topoisomerase V (Topo-V) is the only member of a novel topoisomerase subtype. Topo-V is unique because it is a bifunctional enzyme carrying both topoisomerase and DNA repair lyase activities within the same protein. Previous studies had shown that the topoisomerase domain spans the N-terminus of the protein and is followed by 12 tandem helix–hairpin–helix [(HhH)(2)] domains. There are at least two DNA repair lyase active sites for apurinic/apyrimidinic (AP) site processing, one within the N-terminal region and the second within the C-terminal domain of Topo-V, but their exact locations and characteristics are unknown. In the present study, the N-terminal 78-kDa fragment of Topo-V (Topo-78), containing the topoisomerase domain and one of the lyase DNA repair domains, was characterized by structural and biochemical studies. The results show that an N-terminal 69-kDa fragment is the minimal fragment with both topoisomerase and AP lyase activities. The lyase active site of Topo-78 is at the junction of the fifth and sixth (HhH)(2) domains. From the biochemical and structural data, it appears that Lys571 is the most probable nucleophile responsible for the lyase activity. Our experiments also suggest that Topo-V most likely acts as a Class I AP endonuclease in vivo. Oxford University Press 2013-01 2012-11-02 /pmc/articles/PMC3592480/ /pubmed/23125368 http://dx.doi.org/10.1093/nar/gks1017 Text en © The Author(s) 2012. Published by Oxford University Press. http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/3.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com. |
spellingShingle | Structural Biology Rajan, Rakhi Prasad, Rajendra Taneja, Bhupesh Wilson, Samuel H. Mondragón, Alfonso Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title | Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title_full | Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title_fullStr | Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title_full_unstemmed | Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title_short | Identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase V by structural and functional studies |
title_sort | identification of one of the apurinic/apyrimidinic lyase active sites of topoisomerase v by structural and functional studies |
topic | Structural Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592480/ https://www.ncbi.nlm.nih.gov/pubmed/23125368 http://dx.doi.org/10.1093/nar/gks1017 |
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