Lecture 8 (recording 10)
For different RNA, there are different promoters.
*A number of eukaryotic RNA polymerases required
• Each of these RNAPs(RNA polymerase) is a multi-subunit protein
• Each is responsible for transcription of different RNAs.
-RNA polymerase I: genes (5.8S, 18S, and 28S rRNA genes) get transcribed
-RNA polymerase II: all protein-coding genes get transcribed
-RNA Polymerase III: tRNA genes get transcribed.
Eukaryotic RNAPs’ subunit
*some sub units are common to all three RNAP’s
*some subunits resemble the sub units of Bacterial RNAP’s
+RNAP II unique character : CTD (C terminal domain). it’s a tail attached at subunit 1. *Eukaryotic vs. bacterial RNA polymerases
1) Eukaryotic RNA polymerases require proteins to help position them at the promoter, called:
2) These factors fulfill a similar role to the sigma subunit of the bacterial RNA polymerases
3) Eukaryotic RNA polymerases need to deal with chromosomal structures (more complex… it had
to untangle to produce coherent transcript)
[Transcription of protein-coding genes]
+TFIIB(transcription factor by polymerase II for protein B)
-TATA Box: the sequence TATA highly conserved, found 25-36bp upstream from start site for
-the positioning of the promoter elements are positioned relative to the transcription start point
So they in fact in eukaryotic transcription act