Question

Compare and contrast the strategies of promoter targeting and promoter clearance used by prokaryotic versus eukaryotic RNA polymerases in transcribing mRNA.

Answer 1

In Prokaryotes, the promoter targetting takes place at two short sequences, -10 and -35 positions upstream from the transcription site. Promoter clearance is the last stage of transcription initiation in prokaryotes when RNA polymerase.

In Eukaryotes,the promoter targetting involves multiple transcrption factors that inturn achieves a hyperactive state. During Promoter clearance in Eukaryotes, the TFIIH phosphorylates serine 5 on the carboxyl terminal domain of RNA polymerase II , which leads to recruitment of capping enzyme.