Analysis of DNA cleavage by reverse gyrase from Sulfolobus shibatae B12
Analysis of DNA cleavage by reverse gyrase from Sulfolobus shibatae B12
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DOI：
10.1046/j.1432-1327.1999.00128.x
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发表时间：
1999-02-01
期刊：
影响因子：
--
通讯作者：
Nadal, M
中科院分区：
文献类型：
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作者：
Jaxel, C;Duguet, M;Nadal, M
反向旋转酶是一种 I-5' 拓扑异构酶，可在体外催化正 DNA 超螺旋反应。为了确定这个反应是如何发生的，我们观察了反向旋转酶识别的 DNA 序列。我们使用了其首选底物病毒 SSV1 DNA 的线性 DNA 片段，该片段已被证明在体内呈正超螺旋。选择 SSV1 病毒宿主 Sulfolobus shibatae B12 菌株来生产反向旋转酶。这种天然存在的系统（SSV1 DNA-S. shibatae 反向旋转酶）使我们能够确定哪些 SSV1 DNA 序列被该酶以特别高的选择性结合和切割。我们表明，ATP 的存在减少了获得的裂解复合物的数量，而不可水解的 ATP 类似物腺苷 5'-β,γ-亚氨基]三磷酸则增加了裂解复合物的数量，而不会改变序列特异性。
Reverse gyrase is a type I-5' topoisomerase, which catalyzes a positive DNA supercoiling reaction in vitro. To ascertain how this reaction takes place, we looked at the DNA sequences recognized by reverse gyrase. We used linear DNA fragments of its preferred substrate, the viral SSV1 DNA, which has been shown to be positively supercoiled in vivo. The Sulfolobus shibatae B12 strain, an SSV1 virus host, was chosen for production of reverse gyrase. This naturally occurring system (SSV1 DNA-S. shibatae reverse gyrase) allowed us to determine which SSV1 DNA sequences are bound and cleaved by the enzyme with particularly high selectivity. We show that the presence of ATP decreases the number of cleaved complexes obtained whereas the non-hydrolyzable ATP analog adenosine 5'-[beta,gamma-imido]triphosphate increases it without changing the sequence specificity.