Poster Presentation The 42nd Lorne Conference on Protein Structure and Function 2017

The TAFs of TFIID bind and rearrange the topology of a TATA-less promoter independent of TBP (#166)

Sarah N. Le 1 , Christopher Brown 2 , Stacy Harvey 2 , Jarrod Voss 1 , Kenji Murakami 3 , Hinrich Boeger 2 , Hans Elmlund 1 , Dominika Elmlund 1
  1. Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
  2. Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA, USA
  3. Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA

The general transcription factor TFIID is a core promoter selectivity factor that recognises DNA sequence elements and nucleates the assembly of a pre-initiation complex (PIC). The mechanism by which TFIID recognises the promoter is poorly understood. The TATA box binding protein (TBP) is a subunit of the multi-protein TFIID complex believed to be key to this process. We reconstituted transcription from purified components on a ribosomal protein gene and revealed that TFIIDΔTBP binds and rearranges the promoter DNA topology independent of TBP. TFIIDΔTBP binds ~200 bp of the promoter and changes the DNA topology to a larger extent than the nucleosome core particle. We show that TBP inhibits DNA-binding activities of TFIIDΔTBP and conclude that the complete TFIID complex represents an auto-inhibited state. Furthermore, we show that the DNA binding activities of TFIIDΔTBP are required for assembly of a PIC poised to select the correct transcription start site.