The interaction of the F plasmid killer protein, CcdB, with DNA gyrase: Induction of DNA cleavage and blocking of transcription
The interaction of the F plasmid killer protein, CcdB, with DNA gyrase: Induction of DNA cleavage and blocking of transcription
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DOI：
10.1006/jmbi.1997.1357
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发表时间：
1997-11-07
影响因子：
5.6
通讯作者：
Maxwell, A
中科院分区：
文献类型：
--
作者：
Critchlow, SE;ODea, MH;Maxwell, A
我们研究了F质粒杀伤蛋白CcdB与其细胞内靶DNA旋转酶的相互作用。我们证实了CcdB fan可诱导促旋酶对DNA的切割，并表明当底物为线性DNA时，这种切割反应需要ATP水解，但当使用负超螺旋DNA时，这种切割反应不依赖于水解。在B蛋白和喹诺酮药物存在下可催化DNA切割的促旋酶A蛋白的64 kDa结构域在CcdB存在下不能切割DNA，除非促旋酶A蛋白的C末端33 kDa结构域也存在。CcdB诱导的促旋酶的DNA切割需要最小长度的DNA（>类似于160 bp），而在喹诺酮药物存在下，促旋酶可以切割短得多的DNA分子。我们发现，CcdB，像喹诺酮类，可以形成一个复合物与回旋酶，可以阻止RNA聚合酶的转录。CcdB与促旋酶的相互作用，涉及捕获后链通道中间体的模型建议。我们的结论是，CcdB可以稳定的DNA促旋酶和DNA之间的切割复合物的方式不同于喹诺酮类，但像喹诺酮诱导的切割复合物，CcdB稳定的复合物也可以形成一个障碍，通过聚合酶。(C)出版社：Academic Press Limited。
We have studied the interaction of the F plasmid killer protein CcdB with its intracellular target DNA gyrase. We confirm that CcdB fan induce DNA cleavage by gyrase anti show that this cleavage reaction requires ATP hydrolysis when the substrate is linear DNA, but is independent of hydrolysis when negatively supercoiled DNA is used. The 64 kDa domain of the gyrase A protein, which can catalyse DNA cleavage in the presence of the B protein and quinolone drugs, is unable to cleave DNA in the presence of CcdB unless the C-terminal 33 kDa domain of the gyrase A protein is also present. CcdB-induced DNA cleavage by gyrase requires a minimum length of DNA (> similar to 160 bp), whereas in the presence of quinolone drugs gyrase can cleave much shorter DNA molecules. We show that CcdB, Like quinolones, can form a complex with gyrase which can block transcription by RNA polymerase. A model for the interaction of CcdB with gyrase involving the trapping of a post-strand-passage intermediate is suggested. We conclude that CcdB can stabilise a cleavage complex between DNA gyrase and DNA in a manner distinct from quinolones but, like the quinolone-induced cleavage complex, the CcdB-stabilised complex can also form a barrier to the passage of polymerases. (C) 1997 Academic Press Limited.