Yeung K, Kim S, Reinberg D
Howard Hughes Medical Institute, Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635, USA.
Mol Cell Biol. 1997 Jan;17(1):36-45. doi: 10.1128/MCB.17.1.36.
The heterotetrameric Dr1-DRAP1 transcriptional repressor complex was functionally dissected. Dr1 was found to contain two domains required for repression of transcription. The tethering domain interacts with the TATA box binding protein and directs the repressor complex to the promoter. This tethering domain can be replaced by a domain conferring sequence-specific recognition to the repressor complex. In the absence of the tethering domain, Dr1 interacts with its corepressor DRAP1, but this interaction is not functional. The enhancement of Dr1-mediated repression of transcription by DRAP1 requires the tethering domain. The second domain of Dr1 is the repression domain, which is glutamine-alanine rich. A 65-amino-acid polypeptide containing the repression domain fused to the Ga14 DNA binding domain repressed transcription when directed to TATA-containing and TATA-less promoters. This repression domain was also found to functionally and directly interact with the TATA box binding protein.
对异源四聚体Dr1 - DRAP1转录抑制复合物进行了功能剖析。发现Dr1含有转录抑制所需的两个结构域。锚定结构域与TATA盒结合蛋白相互作用，并将抑制复合物导向启动子。该锚定结构域可被赋予抑制复合物序列特异性识别能力的结构域取代。在没有锚定结构域的情况下，Dr1与其共抑制因子DRAP1相互作用，但这种相互作用无功能。DRAP1增强Dr1介导的转录抑制需要锚定结构域。Dr1的第二个结构域是富含谷氨酰胺 - 丙氨酸的抑制结构域。一个含有与Gal4 DNA结合结构域融合的抑制结构域的65个氨基酸的多肽，当被导向含TATA和不含TATA的启动子时可抑制转录。还发现该抑制结构域与TATA盒结合蛋白在功能上直接相互作用。
