NC2 mobilizes TBP on core promoter TATA boxes

The general transcription factors (GTFs) of eukaryotic RNA polymerase II, in a process facilitated by regulatory and accessory factors, target promoters through synergistic interactions with core elements. The specific binding of the TATA box-binding protein (TBP) to the TATA box has led to the assumption that GTFs recognize promoters directly, producing a preinitiation complex at a defined position. Using biochemical analysis as well as biophysical single-pair Förster resonance energy transfer, we now provide evidence that negative cofactor-2 (NC2) induces dynamic conformational changes in the TBP-DNA complex that allow it to escape and return to TATA-binding mode. This can lead to movement of TBP along the DNA away from TATA.