Struhl K
Mol Cell Biol. 1986 Nov;6(11):3847-53. doi: 10.1128/mcb.6.11.3847-3853.1986.
his3 and pet56 are adjacent Saccharomyces cerevisiae genes that are transcribed in opposite directions from initiation sites that are separated by 200 base pairs. Under normal growth conditions, in which his3 and pet56 are transcribed at similar basal levels, a poly(dA-dT) sequence located between the genes serves as the upstream promoter element for both. In contrast, his3 but not pet56 transcription is induced during conditions of amino acid starvation, even though the critical regulatory site is located upstream of both respective TATA regions. Moreover, only one of the two normal his3 initiation sites is subject to induction. From genetic and biochemical evidence, I suggest that the his3-pet56 intergenic region contains constitutive and inducible promoters with different properties. In particular, two classes of TATA elements, constitutive (Tc) and regulatory (Tr), can be distinguished by their ability to respond to upstream regulatory elements, by their effects on the selection of initiation sites, and by their physical structure in nuclear chromatin. Constitutive and inducible his3 transcription is mediated by distinct promoters representing each class, whereas pet56 transcription is mediated by a constitutive promoter. Molecular mechanisms for these different kinds of S. cerevisiae promoters are proposed.
his3和pet56是酿酒酵母的相邻基因，它们从起始位点以相反方向转录，起始位点相隔200个碱基对。在正常生长条件下，his3和pet56以相似的基础水平转录，位于这两个基因之间的一个聚（dA-dT）序列作为它们两者的上游启动子元件。相比之下，在氨基酸饥饿条件下his3转录被诱导，而pet56转录不被诱导，尽管关键调控位点位于各自TATA区域的上游。此外，两个正常的his3起始位点中只有一个受到诱导。根据遗传学和生物化学证据，我认为his3-pet56基因间区域包含具有不同特性的组成型和诱导型启动子。特别是，两类TATA元件，即组成型（Tc）和调控型（Tr），可以通过它们对上游调控元件的响应能力、对起始位点选择的影响以及它们在核染色质中的物理结构来区分。组成型和诱导型his3转录由代表每一类的不同启动子介导，而pet56转录由一个组成型启动子介导。文中提出了这些不同类型的酿酒酵母启动子的分子机制。
