A conserved core element is functionally important for maize mitochondrial promoter activity in vitro
A conserved core element is functionally important for maize mitochondrial promoter activity in vitro
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DOI：
10.1093/nar/25.20.4055
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发表时间：
1997-10-15
影响因子：
14.9
通讯作者：
Stern, DB
中科院分区：
文献类型：
--
作者：
Caoile, AGFS;Stern, DB
我们先前使用同源的体外转录系统来定义玉米线粒体atpA启动子的功能元件。这些元件包括相对于转录起始位点从-7延伸到+5的中心结构域，以及1- 3bp的上游结构域，其富含嘌呤并且集中在位置-11至-12附近。在中心结构域内存在必需的5 bp核心元件。这些元件在许多线粒体启动子中是保守的，但它们的功能仅针对atpA进行了测试。在这项研究中，我们将突变引入到两个cox 3启动子的相应元件中，并表明虽然核心元件对cox 3启动子活性是必需的，但上游元件突变几乎没有影响，为了确定体外启动子活性所需的最小序列，使用了一系列对应于atpA启动子的短克隆寡核苷酸。虽然用14 bp序列观察到一些活性，但完全活性需要26 bp，这表明核心和上游区域以外的元件可以影响启动子强度。另一系列的克隆表明，改变atpA上游元件和核心元件之间的间距对启动子活性有显着影响，这些结果进一步确定了植物线粒体转录机制的重要特征。
We have previously used a homologous in vitro transcription system to define functional elements of the maize mitochondrial atpA promoter, These elements comprise a central domain extending from -7 to +5, relative to the transcription start site, and an upstream domain of 1-3 bp that is purine rich and centered around positions -11 to -12. Within the central domain lies an essential 5 bp core element. These elements are conserved in many mitochondrial promoters, but their functionality has only been tested for atpA, In this study we have introduced mutations into the corresponding elements of two cox3 promoters and show that while the core element is essential for cox3 promoter activity, upstream element mutations have little or no effect, To define the minimal sequence required for in vitro promoter activity a series of short cloned oligonucleotides corresponding to the atpA promoter was used. While some activity was seen with a 14 bp sequence, full activity required 26 bp, suggesting that elements other than the core and upstream region can influence promoter strength. Another series of clones showed that altered spacing between the upstream and core elements of atpA had a significant effect on promoter activity, These results further define important features of the plant mitochondrial transcriptional machinery.