Initiation Eukaryote promoters are also located upstream from the coding sequence for the transcript. TATA box is necessary but not sufficient CAAT box and GC box are present but not always Synthesis begins with GTP or ATP 5' end is quickly modified to a CAP form with GTP 5' End Capped 2. This is large family of proteins that interact with RNA Pol II in order to facilitate polymerization. Polymerase II Complex Other factors may also be necessary depending on the site such as special transcription factors and enhancers. Enhancers are able to stimulate transcription thousands of bp away.
Enhancers can be upstream, downsteam and even in the sequence.
They are generally cell specific. Virus can also have enhancers that are tissue and species specific. Termination Termination of transcription is not well understood. The transcript is transported out of the nucleus.