Open AccessYY1 transcriptional initiator: Protein interactions and association with a DNA site containing unpaired strands
Author(s) -
Anny Usheva,
Thomas Shenk
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.24.13571
Subject(s) - yy1 , transcription factor ii b , transcription factor ii a , hmg box , microbiology and biotechnology , biology , dna , dna supercoil , transcription (linguistics) , polymerase , binding site , base pair , dna clamp , dna binding site , transcription factor , promoter , dna binding protein , genetics , rna , rna dependent rna polymerase , gene , reverse transcriptase , dna replication , gene expression , linguistics , philosophy
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.