Coulombe B, Killeen M, Liljelund P, Honda B, Xiao H, Ingles C J, Greenblatt J
Banting and Best Department of Medical Research, University of Toronto, Ontario.
Gene Expr. 1992;2(2):99-110.
The TATA box binding transcription factor TFIID of S. cerevisiae was used as a ligand for affinity chromatography. Polypeptides that bind specifically to yeast TFIID (TFIID-associated proteins, DAPs) were purified from human HeLa (heDAPs) and calf thymus (ctDAPs) whole cell extracts. Both heDAP and ctDAP fractions altered the binding of TFIID to the TATA element, and substituted for the TFIIA transcription activity in a reconstituted in vitro system. The heDAP fraction also behaved like TFIIA in its ability to form a promoter-TFIID-TFIIA complex and to recruit TFIIB to such a complex. The interaction of DAPs with TFIID can confer heat-resistance (47 degrees C) on recombinant yeast or human TFIID. SDS-PAGE analysis revealed that three polypeptides from HeLa extracts specifically bound to yTFIID columns (heDAP35, heDAP21, and heDAP12). These data suggest that a multi-subunit transcription factor with the properties of TFIIA can bind to TFIID in the absence of DNA.
酿酒酵母的TATA框结合转录因子TFIID被用作亲和层析的配体。从人HeLa（heDAPs）和小牛胸腺（ctDAPs）全细胞提取物中纯化出与酵母TFIID特异性结合的多肽（TFIID相关蛋白，DAPs）。heDAP和ctDAP组分均改变了TFIID与TATA元件的结合，并在重组体外系统中替代了TFIIA的转录活性。heDAP组分在形成启动子-TFIID-TFIIA复合物以及将TFIIB招募到此类复合物的能力方面也表现得与TFIIA相似。DAPs与TFIID的相互作用可赋予重组酵母或人TFIID耐热性（47摄氏度）。SDS-PAGE分析显示，来自HeLa提取物的三种多肽特异性结合到yTFIID柱上（heDAP35、heDAP21和heDAP12）。这些数据表明，具有TFIIA特性的多亚基转录因子可在无DNA的情况下与TFIID结合。
