Here, the early steps of activator-dependent transcription in yeast are examined by using cryo-electron microscopy to study the transcription activator Rap1 in complex with the general transcription factors TFIID and TFIIA and with yeast enhancer–promoter DNA. A model is proposed whereby interactions between Rap1 and TFIIA convey activating signals to TFIID. Moreover, a Rap1-dependent DNA loop is visualized between the enhancer and the promoter.
- Gabor Papai
- Manish K. Tripathi
- Patrick Schultz
