Eukaryotic Transcription Flashcards
What are TBP’s?
TATA- box binding proteins
subunit of TFIID
What are TAF’s?
TATA-box binding protein associated factors
How does initiation start?
TBP binds to TATA box
5 more TF’s bind and Rpol
form Pre-Initiation Complex
What is the function of TFIID?
Recognise TATA box +
Regulate DNA binding by TBP
What is the function of TFIIB?
Recognises BRE element
Puts Rpol at Transcription start site
What is the function of TFIIF?
Stabilises interaction of Rpol and TBP
Helps attract TFIIE+H
What is the function of TFIIE?
Attracts and regulates TFIIH
What is the function of TFIIH?
ATPase and Kinase
ATPase- helps move DNA into Rpol complex
(abortive initiation)
Kinase- Phosphorylates CTD region of Rpol
What enables the Polymerase to escape the promoter?
phosphorylation of the CTD region by TFIIH
what is 5’ capping?
7-methyl G cap added to 5’ end and bound by Cap Binding Complex
during 3’ Polyadenylation where is the pre-mRNA cleaved?
between AAUAAA consensus and a GC rich sequence
What 2 factors aid polyadenylation?
Cleavage and Polyadenylation specificity factor
Cleavage stimulation factor
What does Poly A Polymerase (PAP) do?
adds approx 20 Adenines to 3’ end
What happens to the RNA transcribed after the poly A tail?
degraded by a 5’ exonuclease Xnr2
no cap on it
