A regulated two-step mechanism of TBP binding to DNA: a solvent-exposed surface of TBP inhibits TATA box recognition.
The TATA box binding protein TBP plays a universally important role in eukaryotic nuclear transcription. By mutagenesis, we have discovered a solvent-exposed surface of the structured TBP core domain that is important for inhibition of the DNA binding and DNA-bending activities of full-length wild-type TBP. Full-length wild-type TBP initially binds the TATA box to form an unstable complex containing unbent DNA, and then it slowly forms a stable complex containing bent DNA. TFIIB greatly accelerates formation of a bent TFIIB-TBP-TATA box complex, and the inhibitory DNA binding surface of TBP contributes to the cooperativity of binding to TFIIB. Using TBP and TFIIB, we show that TBP can bind the TATA box through a regulated two-step mechanism, involving a transition from unbent complex to bent complex.
Zhao
Xuemei
X
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Herr
Winship
W
D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008957:Models, Genetic; D008958:Models, Molecular; D009154:Mutation; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D011993:Recombinant Fusion Proteins; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors; D004247:DNA