DNA-binding determinants of the alpha subunit of RNA polymerase: Novel DNA-binding domain architecture
DNA-binding determinants of the alpha subunit of RNA polymerase: Novel DNA-binding domain architecture
复制标题
DOI：
10.1101/gad.10.1.16
复制
发表时间：
1996-01-01
影响因子：
10.5
通讯作者：
Gourse, RL
中科院分区：
文献类型：
--
作者：
Gaal, T;Ross, W;Gourse, RL
大肠杆菌RNA聚合酶α -亚基通过其羧基末端结构域（α CTD）与某些启动子中的识别元件上游（UP）元件结合。我们使用遗传和生化技术鉴定了α CTD中对up元件依赖转录和DNA结合重要的残基。这些残基出现在α CTD的两个区域，接近但不同于与某些转录激活因子相互作用的重要残基。我们用核磁共振波谱法确定了α - CTD的二级结构。alpha CTD包含一个非标准螺旋，后面跟着四个alpha螺旋。α - CTD的两个对DNA结合很重要的区域对应于第一个α -螺旋和第三和第四个α -螺旋之间的环。α - CTD DNA结合域结构不同于迄今为止发现的任何DNA结合结构，我们提出α - CTD具有与DNA相互作用的新模式。我们的研究结果提出了转录起始过程中α - CTD-DNA和α - CTD-DNA-激活子相互作用的模型。
The Escherichia coli RNA polymerase alpha-subunit binds through its carboxy-terminal domain (alpha CTD) to a recognition element, the upstream (UP) element, in certain promoters. We used genetic and biochemical techniques to identify the residues in alpha CTD important for UP-element-dependent transcription and DNA binding. These residues occur in two regions of alpha CTD, close to but distinct from, residues important for interactions with certain transcription activators. We used NMR spectroscopy to determine the secondary structure of alpha CTD. alpha CTD contains a nonstandard helix followed by four alpha-helices. The two regions of alpha CTD important for DNA binding correspond to the first alpha-helix and the loop between the third and fourth alpha-helices. The alpha CTD DNA-binding domain architecture is unlike any DNA-binding architecture identified to date, and we propose that alpha CTD has a novel mode of interaction with DNA. Our results suggest models for alpha CTD-DNA and alpha CTD-DNA-activator interactions during transcription initiation.