Decatenation is a crucial in vivo reaction of DNA topoisomerases in DNA replication and is frequently used in in vitro drug screening. Usually this reaction is monitored using kinetoplast DNA as a substrate, although this assay has several limitations. Here we have engineered a substrate for Tn3 resolvase that generates a singly-linked catenane that can readily be purified from the DNA substrate after restriction enzyme digestion and centrifugation. We show that this catenated substrate can be used with high sensitivity in topoisomerase assays and drug-inhibition assays.

中文翻译：

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使用单连接的连锁底物对 DNA 拓扑异构酶进行新的去链化验。

去链是DNA 拓扑异构酶在 DNA 复制中的关键体内反应，常用于体外药物筛选。通常使用动质体 DNA 作为底物监测该反应，尽管该检测有几个限制。在这里，我们设计了 Tn 3分解酶的底物，它生成单链链，在限制性内切酶消化和离心后可以很容易地从 DNA 底物中纯化。我们表明这种链状底物可以在拓扑异构酶测定和药物抑制测定中以高灵敏度使用。