STRINGENT SPACING REQUIREMENTS FOR TRANSCRIPTION ACTIVATION BY CRP
STRINGENT SPACING REQUIREMENTS FOR TRANSCRIPTION ACTIVATION BY CRP
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DOI：
10.1016/0092-8674(90)90118-x
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发表时间：
1990-08-24
期刊：
影响因子：
64.5
通讯作者：
BUSBY, S
中科院分区：
文献类型：
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作者：
GASTON, K;BELL, A;BUSBY, S
环 AMP 受体蛋白-cAMP 复合物 (CRP-cAMP) 在多个大肠杆菌启动子上游的不同距离处结合并激活转录。我们构建了一个模型系统，其中共有 CRP 结合位点位于 meIR 启动子上游的不同距离处。当 CRP-cAMP 与多个位置结合时，CRP-cAMP 会激活 meIR 的转录，所有这些位置都位于 DNA 螺旋的同一面上。转录被强烈激活的两个距离与 CRP-cAMP 结合到经过充分研究的 galP1 和 lac 启动子上游的距离完全一致。合成启动子的足迹显示，尽管 CRP-cAMP 在每种情况下的结合距离不同，但 RNA 聚合酶与其 -10 区域具有相同的接触。体外动力学分析表明，CRP-cAMP 以相似但不同的方式激活这些启动子的转录。提出了一个模型来解释这种二位激活。
The cyclic AMP receptor protein-cAMP complex (CRP-cAMP) binds at a variety of distances upstream of several E. col promoters and activates transcription. We have constructed a model system in which a consensus CRP binding site is placed at different distances upstream of the meIR promoter. CRP-cAMP activates transcription from meIR when bound at a number of positions, all of which lie on the same face of the DNA helix. The two distances at which transcription is strongly activated correspond exactly to those at which CRP-cAMP binds upstream of the well-studied galP1 and lac promoters. Footprinting of the synthetic promoters reveals that RNA polymerase makes identical contacts with their -10 regions even though CRP-cAMP binds at a different distance in each case. Kinetic analysis in vitro indicates that CRP-cAMP activates transcription from these promoters in similar but distinct ways. A model is proposed to explain this two-position activation.