TopA, the Sulfolobus solfataricus topoisomerase III, is a decatenase

Anna H. Bizard, Xi Yang, Hélène Débat, Jonathan M. Fogg, Lynn Zechiedrich, Terence R. Strick, Florence Garnier, Marc Nadal*

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

12 Citationer (Scopus)
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Abstract

DNA topoisomerases are essential enzymes involved in all the DNA processes and among them, type IA topoisomerases emerged as a key actor in the maintenance of genome stability. The hyperthermophilic archaeon, Sulfolobus solfataricus, contains three topoisomerases IA including one classical named TopA. SsoTopA is very efficient at unlinking DNA catenanes, grouping SsoTopA into the topoisomerase III family. SsoTopA is active over a wide range of temperatures and at temperatures of up to 85 °C it produces highly unwound DNA. At higher temperatures, SsoTopA unlinks the two DNA strands. Thus depending on the temperature, SsoTopA is able to either prevent or favor DNA melting. While canonical topoisomerases III require a single-stranded DNA region or a nick in one of the circles to decatenate them, we show for the first time that a type I topois merase, SsoTopA, is able to efficiently unlink covalently closed catenanes, with no additional partners. By using single molecule experiments we demonstrate that SsoTopA requires the presence of a short single-stranded DNA region to be efficient. The unexpected decatenation property of SsoTopA probably comes from its high ability to capture this unwound region. This points out a possible role of TopA in S. solfataricus as a decatenase in Sulfolobus.

OriginalsprogEngelsk
TidsskriftNucleic Acids Research
Vol/bind46
Udgave nummer2
Sider (fra-til)861-872
Antal sider12
ISSN0305-1048
DOI
StatusUdgivet - 2018
Udgivet eksterntJa

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