EVIDENCE OF DNA BENDING IN TRANSCRIPTION COMPLEXES IMAGED BY SCANNING FORCE MICROSCOPY
EVIDENCE OF DNA BENDING IN TRANSCRIPTION COMPLEXES IMAGED BY SCANNING FORCE MICROSCOPY
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DOI：
10.1126/science.8503010
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发表时间：
1993-06-11
期刊：
影响因子：
56.9
通讯作者：
BUSTAMANTE, C
中科院分区：
文献类型：
--
作者：
REES, WA;KELLER, RW;BUSTAMANTE, C
大肠杆菌RNA聚合酶与含有λ P（L）启动子的DNA的复合物已被沉积在云母上，并在空气中用扫描力显微镜成像。地形图像揭示了聚合酶相对于DNA模板的总体空间关系。DNA在含有与启动子结合的RNA聚合酶的开放启动子复合物中出现弯曲，并且在其中RNA聚合酶合成了15个核苷酸转录物的延伸复合物中出现更严重的弯曲。这种差异可能与伴随开放启动子复合物成熟为延伸复合物的构象变化有关，并表明延伸复合物的形成涉及聚合酶和DNA模板之间的空间关系的相当大的修改。
Complexes of Escherichia coli RNA polymerase with DNA containing the lambda P(L) promoter have been deposited on mica and imaged in air with a scanning force microscope. The topographic images reveal the gross spatial relations of the polymerase relative to the DNA template. The DNA appears bent in open promoter complexes containing RNA polymerase bound to the promoter and appears more severely bent in elongation complexes in which RNA polymerase has synthesized a 15-nucleotide transcript. This difference could be related to the conformational changes that accompany the maturation of open promoter complexes into elongation complexes and suggests that formation of the elongation complex involves a considerable modification of the spatial relations between the polymerase and the DNA template.