eukaryotic mRNA transcription Flashcards
what transcription factor binds to the TATA box?
TBP (part of TFIID)
describe the steps and transcriiption factors requiredd to form the pre-initiation complex;
TFIID and TFIIB bind to the promoter
TFIIF brings RNA polymerase in
TFIIE and TFIIH bind
After the closed complex is formed…
TFIIH catalyzes unwinding of DNA for the open complex (pre initiation complex)
The activity of the 2 helicase subunits (XPB and XPD) of TFIIH are required
what does a binding experiment look at?
formation of protein-DNA complexes
what was TFIIA once described as?
a general transcription factor and was originally thought to be essential for transcription from many class 2 nuclear gene promoters
what is TFIIA now best described as?
a coactivator that supports regulation of polymerase 2 transcription
what subunits of Rpb1 are needed for phosphorylation?
Cdk7 and cyclin H
what subunits of Rpb1 are needed for forming the open complex?
XPB and XPD
what is TTDA (a subunit of Rpb1) needed for?
DNA repair
what does a mutation in XPB and XPD cause?
Xenoderma pigmentosum:
Decreased ability to repair DNA
what does mutations in TTDA cause?
Trichothiodystrophy
what is TFIIH required for?
open complex formation
Plays a role in the pathway that detects and repairs damage to DNA
what happens when RNA polymerase leaves the promoter?
The general transcription factors are left behind
CTD of Rpb1 has become phosphorylated
mRNA is capped
Other proteins and complexes will associate with the enzyme
what 7 amino acid sequence does the C terminal of Rpb1 consist of?
Tyr-ser-Pro-thr-ser-pro-ser
what does serine phosphorylation do?
signals the correct order of the subsequent mRNA processing steps
when is the 5th serine phosphorylated?
as RNA polymerase 2 clears the promoter region
