Modular structure of the full-length DNA gyrase B subunit revealed by small-angle X-ray scattering
Modular structure of the full-length DNA gyrase B subunit revealed by small-angle X-ray scattering
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DOI：
10.1016/j.str.2007.01.013
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发表时间：
2007-03-01
期刊：
影响因子：
5.7
通讯作者：
Maxwell, Anthony
中科院分区：
文献类型：
--
作者：
Costenaro, Lionel;Grossmann, J. Gunter;Maxwell, Anthony
DNA促旋酶是唯一能够将负超螺旋引入DNA的拓扑异构酶，对细菌的转录和复制至关重要;在人类中不存在，它是抗菌药物的成功靶点。从溶液中的生物物理实验，我们报告了一个结构模型，在类似的12-15埃分辨率的全长B亚基（GyrB）。超电泳分析表明GyrB主要是一个非小叶单体。GyrB的小角X射线散射数据的从头算建模始终产生一个“蝌蚪”样的信封。它使我们能够提出一个组织的GyrB成三个域-ATP酶，Toprim，和尾巴-基于他们的晶体学和建模结构。我们的研究揭示了GyrB的模块化组织，并指出其潜在的灵活性，需要在促旋酶催化循环。它提供了重要的见解超螺旋机制的促旋酶，并提出了新的研究路线。
DNA gyrase, the only topoisomerase able to introduce negative supercoils into DNA, is essential for bacterial transcription and replication; absent from humans, it is a successful target for antibacterials. From biophysical experiments in solution, we report a structural model at similar to 12-15 angstrom resolution of the full-length B subunit (GyrB). Analytical ultracentrifugation shows that GyrB is mainly a nonglobular monomer. Ab initio modeling of small-angle X-ray scattering data for GyrB consistently yields a "tadpole"-like envelope. It allows us to propose an organization of GyrB into three domains-ATPase, Toprim, and Tail-based on their crystallographic and modeled structures. Our study reveals the modular organization of GyrB and points out its potential flexibility, needed during the gyrase catalytic cycle. It provides important insights into the supercoiling mechanism by gyrase and suggests new lines of research.