Structural basis of transcription activation

Transcription activation all about timing Regulating transcription by RNA polymerase (RNAP) is central to controlling gene expression. Transcription factors influence the activity of the RNAP. Feng et al. determined the crystal structure of a bacterial transcription activation complex. The transcription activator protein (TAP) converts the closed RNAP-promoter complex into an open complex through simple stabilizing protein-protein interactions with RNAP. The critical contacts did not go through the RNAP active center or the RNAP clamp. Instead, it seems that the timing of the interaction during transcription complex formation is critical for activation. Science , this issue p. 1330