title: YY1 transcriptional initiator: protein interactions and association with a DNA site containing unpaired strands.
abstract: 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.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, NJ 08544-1014, USA.
authors.forename: A
authors.initials: A
authors.lastname: Usheva
authors.forename: T
authors.initials: T
authors.lastname: Shenk
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004278:DNA, Superhelical / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D006367:HeLa Cells; D006801:Humans; D012319:RNA Polymerase II / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D050986:YY1 Transcription Factor
chemical_list: D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D011993:Recombinant Fusion Proteins; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; D004247:DNA; D012319:RNA Polymerase II