Structural basis of transcription:: RNA polymerase II at 2.8 Ångstrom resolution
Structural basis of transcription:: RNA polymerase II at 2.8 Ångstrom resolution
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DOI：
10.1126/science.1059493
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发表时间：
2001-06-08
期刊：
影响因子：
56.9
通讯作者：
Kornberg, RD
中科院分区：
文献类型：
--
作者：
Cramer, P;Bushnell, DA;Kornberg, RD
10-亚基酵母RNA聚合酶II的结构已从两种晶体形式在2.8和3.1埃分辨率。结构的比较揭示了聚合酶分为四个移动的模块，包括一个钳，以前显示摆动的活性中心。在2.8埃结构中，夹钳处于打开状态，允许直启动子DNA进入以启动转录。在转录过程中，从夹子延伸的三个环可能在RNA解旋和DNA重绕中起作用。一个2.8埃的傅立叶图显示两个金属离子在活性位点，一个持续绑定和其他可能在RNA合成过程中交换。结果还提供了证据，RNA出口附近的羧基末端重复结构域，耦合合成RNA加工的酶结合到这个域。
Structures of a 10-subunit yeast RNA polymerase II have been derived from two crystal forms at 2.8 and 3.1 angstrom resolution. Comparison of the structures reveals a division of the polymerase into four mobile modules, including a clamp, shown previously to swing over the active center. In the 2.8 angstrom structure, the clamp is in an open state, allowing entry of straight promoter DNA for the initiation of transcription. Three Loops extending from the clamp may play roles in RNA unwinding and DNA rewinding during transcription. A 2.8 angstrom difference Fourier map reveals two metal ions at the active site, one persistently bound and the other possibly exchangeable during RNA synthesis. The results also provide evidence for RNA exit in the vicinity of the carboxyl-terminal repeat domain, coupling synthesis to RNA processing by enzymes bound to this domain.