The co-transcriptional processing of RNA depends on the precisely timed recruitment of different factors to the elongating transcript, which depends on the phosphorylation state of the C-terminal domain (CTD) of RNA polymerase II. Varani and coworkers show that two transcription termination factors, Rtt103 and Pcf1, bind specifically and cooperatively to Ser2-phosphorylated CTD. This provides a way to ensure that proper polyadenylation occurs only where Ser2 phosphorylation density is highest.
- Bradley M Lunde
- Steve L Reichow
- Gabriele Varani
