University of Central Florida (UCF) PCB4524 Molecular Biology II Practice Exam 1

After TFIIH phosphorylates the carboxy-terminal domain (CTD) of RNA polymerase II during transcription, the next significant event is the recruitment of elongation factors. This phosphorylation serves as a crucial signal that transitions the transcription machinery from the initiation phase to the elongation phase.

The phosphorylation of the CTD is a key regulatory step, facilitating the association of various elongation factors that enhance RNA polymerase II's ability to synthesize mRNA. These elongation factors assist in modifying the RNA polymerase structure, ensuring that it can efficiently move along the DNA template, as well as help in the processing of the nascent RNA transcript, including capping and splicing.

The subsequent engagement of elongation factors is vital for the elongation phase of transcription, as they promote the continuous synthesis of the mRNA molecule.