Patty eukaryotic gene expression lecture 4 Flashcards
(20 cards)
What is NELF
Negative elongation factor. Bind to the CTD at the promoter proximal pause and prevents elongation. This allows for the 5’ cap to be added
What is DSIF
DRB sensitivity inducing factor. Binds CTD and Inhibits elongation during the promoter proximal pause, allows 5’ cap to be added
What Phosphorylates serine 5
TFIIH
What phosphorylates serine 2
CTDK-1 part of the P-TEFb
What does P-TEFb phosphorylate
Serine 2 via its CTD-k1 domain as well as NELF and DSIF
How many NT are added before TFIIB dissociates and promoter escape occurs
8-9NT
How many NT are added before the promoter proximal pause
20-50NT
What happens when NELF is Phosphorylated
It dissociates from the CTD and elongation inhibition is relieved
WHat happens when DSIF is phosphorylated
It switches it activity from inhibition to activation and recruits elongation activators such as ELONGIN
What happens when serine 2 is phosphorylated
3’ processing proteins are recruited to the CTD
What happens when the serine 5 is phosphorylated
5’ Capping
What removes the phosphate from serine 5
Serine 5 phsophatase
What is the complex called after it as escaped the promoter
The early elongation complex
When does capping occur
Co transcriptionally after the serine 5 has been added
Which domain has the CTD
B’ like domain
What cleaves the gamma phosphate from the 1st NT in the transcript
Nucleotide phosphorylase
Which 2 phosphate groups form the 5’ to 5’ linkage in the capping reaction
Beta phosphate in transcript with the alpha phosphate in GTP
What enzyme adds Methyl group to Guanine cap
Guanylyl-N7-methyltransferase
What adds methyl groups to OH groups in other transcript nucleotides?
Nucleotide-2-O-methyltransferase adds me to 2’ OH in the sugars of other NTs
What is the Methyl donor for the capping reaction
SAM s-adenosyl-methionine