TC, AN UNUSUAL PROMOTER ELEMENT REQUIRED FOR CONSTITUTIVE TRANSCRIPTION OF THE YEAST HIS3 GENE
TC, AN UNUSUAL PROMOTER ELEMENT REQUIRED FOR CONSTITUTIVE TRANSCRIPTION OF THE YEAST HIS3 GENE
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DOI：
10.1128/mcb.10.9.4447
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发表时间：
1990-09-01
影响因子：
5.3
通讯作者：
STRUHL, K
中科院分区：
文献类型：
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作者：
MAHADEVAN, S;STRUHL, K
TC是组成型his 3转录所需的近端启动子元件，其在不存在典型TATA元件（TR）的情况下发生，并且从+1位点起始。与TR不同，TC元件不响应GCN 4或GAL 4激活蛋白的转录刺激。缺失、取代和点突变的分析表明，TC定位在核苷酸-54和-83之间，并且是序列依赖性元件，因为它不能在功能上被其他DNA序列取代。然而，与典型启动子元件的行为相反，通过碱基对取代来消除TC功能是令人惊讶地困难的。在15个衍生物中，TC区平均有4个取代，占所有可能的单一变化的40%，只有1个使TC元件失活。此外，突变体和杂交元件的表型表明，TC的失活需要多个变化。TC和起始区之间的间距可以在30个碱基对的范围内变化，而不会显著影响+1位点的转录水平。根据这些结果，我们认为TC可能不与TFIID或其他一些典型的序列特异性转录因子相互作用，而是可能通过其DNA结构直接或间接地影响转录。
TC is the proximal promoter element required for constitutive his3 transcription that occurs in the absence of the canonical TATA element (TR) and is initiated from the +1 site. The TC element, unlike TR, does not respond to transcriptional stimulation by the GCN4 or GAL4 activator protein. Analysis of deletion, substitution, and point mutations indicates that TC mapped between nucleotides -54 and -83 and is a sequence-dependent element because it could not be functionally replaced by other DNA sequences. However, in contrast to the behavior of typical promoter elements, it was surprisingly difficult to eliminate TC function by base pair substitutions. Of 15 derivatives averaging four substitutions in the TC region and representing 40% of all possible single changes, only 1 inactivated the TC element. Moreover, the phenotypes of mutant and hybrid elements indicated that inactivation of TC required multiple changes. The spacing between TC and the initiation region could be varied over a 30-base-pair range without significantly affecting the level of transcription from the +1 site. From these results, we consider it possible that TC may not interact with TFIID or some other typical sequence-specific transcription factor, but instead might influence transcription, either directly or indirectly, by its DNA structure.