YY1 transcriptional initiator: Protein interactions and association with a DNA site containing unpaired strands

作者：Anny Usheva, Thomas E. Shenk · 发表于：Proceedings of the National Academy of Sciences · 年份：1996 · DOI：10.1073/pnas.93.24.13571 · 被引用次数：106 · 研究领域：Genomics and Chromatin Dynamics、RNA and protein synthesis mechanisms、RNA Research and Splicing

The Ying-Yang 1 protein (YY1) DNA-binding site functions as an initiator element at which YY1, transcription factor IIB (TFIIB), and RNA polymerase II sponsor basal transcription from a supercoiled DNA template. We show that TFIIB binds to YY1, stabilizing its interaction with DNA, and YY1 contacts the large subunit of polymerase II, directing it to the initiation site. YY1 directs initiation from linear DNA containing mismatched sequences within its binding site, leading us to infer that supercoiling facilitates the separation of DNA strands and to suggest that YY1 likely remains bound to the start site as DNA strands separate during initiation. These results provide a mechanistic basis for transcriptional initiation directed by YY1 in the absence of the TATA box-binding protein.