DNA transport by a type II topoisomerase: Direct evidence for a two-gate mechanism
DNA transport by a type II topoisomerase: Direct evidence for a two-gate mechanism
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DOI：
10.1073/pnas.93.9.4057
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发表时间：
1996-04-30
影响因子：
11.1
通讯作者：
Wang, JC
中科院分区：
文献类型：
--
作者：
Roca, J;Berger, JM;Wang, JC
最近的生化和晶体学结果表明，II型DNA拓扑异构酶的作用就像一个atp调节钳，两端有两组颚：DNA结合酶可以通过一组颚接纳第二个DNA；结合ATP后，这个DNA通过第一个DNA中酶介导的开口，并通过另一组颚从酶中排出。在酵母DNA拓扑异构酶二聚体界面上引入可逆二硫键的实验证实了这一机制。第二个DNA被发现通过酶的n端部分形成的门进入酶，并通过门剂量到达C端。
Recent biochemical and crystallographic results suggest that a type II DNA topoisomerase acts as an ATP-modulated clamp with two sets of jaws at opposite ends: a DNA-bound enzyme can admit a second DNA through one set of jaws; upon binding ATP, this DNA is passed through an enzyme-mediated opening in the first DNA and expelled from the enzyme through the other set of jaws. Experiments based on the introduction of reversible disulfide links across one dimer interface of yeast DNA topoisomerase II have confirmed this mechanism. The second DNA is found to enter the enzyme through the gate formed by the N-terminal parts of the enzyme and leave it through the gate dose to the C termini.