Duan and Kaushik et al. reveal the structural basis of how Escherichia coli and Thermus thermophilus RNA polymerases initiate transcription from Np4A alarmones producing Np4-capped transcripts. The caps form various interactions with a polymerase during initial steps, influencing capping efficiency.
- Wenqian Duan
- Abhishek Kaushik
- Alexander Serganov