The yeast his3 promoter contains at least two distinct elements.
The yeast his3 promoter contains at least two distinct elements.
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酵母 his3 启动子包含至少两个不同的元件。
DOI：
10.1073/pnas.79.23.7385
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发表时间：
1982
影响因子：
11.1
通讯作者：
Struhl,K
中科院分区：
文献类型：
--
作者：
Struhl,K
65 个突变的表型分析表明酵母 his3 启动子由至少两个独立的 DNA 区域组成。每一个都是必要的，但对于 his3 表达的野生型水平而言，两者都不够。破坏任一启动子元件的缺失突变使his3表达不良或根本不表达。上游元件位于转录起始位点（核苷酸-112至-155）之前的112和155个碱基对之间。衍生物的比较强烈表明下游元件映射在核苷酸-32和-52之间的某处并且包括核苷酸-45和-52之间的序列。该位置与大多数真核基因之前的保守序列（TATA 框区域）一致。通过使用 his3 序列被大肠杆菌噬菌体 M13 DNA 的小片段替换的衍生物，确立了 his3 启动子的三个特性。首先，his3 TATA盒缺失无法表达his3，因为它们缺乏特定序列，而不是因为它们破坏了其他序列之间的间隔关系。其次，TATA 框区域可以在功能上被包含 TATA 样序列的 M13 DNA 片段的单向替换。第三，两个元件之间的距离（通常为 90 个碱基对）可以在 40 到 160 个碱基对之间变化，而不会显着影响启动子功能。这些结果强烈表明，与大肠杆菌对应物不同，酵母RNA聚合酶II不会同时结合两个启动子元件，并且它们进一步支持了上游元件不是转录活性结合位点的一部分的观点。 his3 上游启动子元件在长距离和可变距离上发挥作用的能力与病毒增强子序列的特性相似，并且让人想起酵母中的位置效应。
Phenotypic analysis of 65 mutations indicates that the yeast his3 promoter is composed of at least two separate regions of DNA. Each is necessary, but neither is sufficient for wild-type levels of his3 expression. Deletion mutations that destroy either promoter element express his3 poorly or not at all. The upstream element is located between 112 and 155 base pairs before the site of transcriptional initiation (nucleotides -112 to -155). A comparison of derivatives strongly suggests that the downstream element maps somewhere between nucleotides -32 and -52 and includes a sequence between nucleotides -45 and -52. This location coincides with sequences conserved before most eukaryotic genes(the TATA box region). By using derivatives in which his3 sequences are replaced by a small fragment of coliphage M13 DNA, three properties of the his3 promoter were established. First, his3 TATA box deletions fail to express his3 because they lack specific sequences and not because they disrupt spacing relationships between other sequences. Second, the TATA box region can be replaced functionally by the one orientation of the M13 DNA fragment that contains a TATA-like sequence. Third, the distance between the two elements (normally 90 base pairs) can be varied between 40 and 160 base pairs without markedly affecting promoter function. These results strongly suggest that yeast RNA polymerase II, unlike its Escherichia coli counterpart, does not bind simultaneously to both promoter elements, and they add further support to the view that the upstream element is not part of a transcriptionally competent binding site. This ability of the his3 upstream promotor element to act at a long and variable distance is similar to properties of viral enhancer sequences and is reminiscent of position effects in yeast.