Singer V L, Wobbe C R, Struhl K
Department Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.
Genes Dev. 1990 Apr;4(4):636-45. doi: 10.1101/gad.4.4.636.
We created a library of DNA molecules in which the required TATA element of a yeast gal-his3 promoter is replaced by random-sequence oligomers averaging 16 bp in length. Surprisingly, 1% of such random sequences functionally replace the native yeast TATA element. In many cases, sequences completely unrelated to the consensus TATA element (TATAAA) stimulate transcription with equal or increased efficiency. Transcription mediated by these synthetic elements requires GAL4 and is initiated from normal his3 initiation sites, suggesting that it occurs by a mechanism indistinguishable from that involving wild-type TATA elements. Many, but not all, of these elements act as substrates for yeast TFIID in reconstituted transcription reactions in vitro. These observations indicate that yeast TFIID can stimulate transcription from TATA elements whose sequences differ from the consensus, and they suggest the possibility of alternative factors that may provide a related function for transcriptional activation.
我们构建了一个DNA分子文库，其中酵母半乳糖-组氨酸3启动子所需的TATA元件被平均长度为16个碱基对的随机序列寡聚物所取代。令人惊讶的是，1%的此类随机序列在功能上可替代天然酵母TATA元件。在许多情况下，与共有TATA元件（TATAAA）完全无关的序列能以相同或更高的效率刺激转录。由这些合成元件介导的转录需要GAL4，并从正常的组氨酸3起始位点起始，这表明其发生机制与涉及野生型TATA元件的机制无法区分。在体外重组转录反应中，许多（但不是全部）这些元件可作为酵母TFIID的底物。这些观察结果表明酵母TFIID可刺激来自序列与共有序列不同的TATA元件的转录，并且它们提示了可能存在替代因子，这些替代因子可为转录激活提供相关功能。
