Hoey T, Dynlacht B D, Peterson M G, Pugh B F, Tjian R
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Cell. 1990 Jun 29;61(7):1179-86. doi: 10.1016/0092-8674(90)90682-5.
To investigate the biochemical mechanisms involved in interactions between regulatory factors and the general transcription complex, we have cloned, expressed, and characterized the Drosophila gene encoding the TATA binding protein, dTFIID. Comparison of the protein sequences of the Drosophila and yeast TATA binding proteins reveals a bipartite organization consisting of a highly conserved, basic carboxy-terminal domain and a nonconserved amino-terminal region rich in Gln, Gly, Ser, and Met residues. Purified dTFIID protein binds specifically to the TATA sequence and activates basal-level transcription, and the conserved carboxy-terminal half of the molecule is sufficient for both activities. Partially purified TFIID from Drosophila cells mediates activation by the transcription factor Sp1. In contrast, purified dTFIID expressed from the cloned gene is unable to support Sp1-dependent activation, suggesting that other factors may be required to mediate interactions between upstream activators like Sp1 and the TATA binding protein.
为了研究调控因子与通用转录复合体之间相互作用所涉及的生化机制，我们克隆、表达并鉴定了果蝇中编码TATA结合蛋白dTFIID的基因。果蝇和酵母TATA结合蛋白的蛋白质序列比较显示，其具有由高度保守的碱性羧基末端结构域和富含Gln、Gly、Ser和Met残基的非保守氨基末端区域组成的二分组织。纯化的dTFIID蛋白特异性结合TATA序列并激活基础水平转录，并且该分子保守的羧基末端一半对于这两种活性都是足够的。从果蝇细胞中部分纯化的TFIID介导转录因子Sp1的激活。相比之下，从克隆基因表达的纯化dTFIID不能支持Sp1依赖的激活，这表明可能需要其他因子来介导像Sp1这样的上游激活剂与TATA结合蛋白之间的相互作用。
