Lecture, RNA Poly parts Flashcards
3 steps for transcription for bacterial gene
Initiation, elongation, termination
sigma factor purpose?
Assists RNA polymerase to bind to specific promoters, (remember, NOT done through a chem rxn!!)
Holoenzyme meaning?
An protein needed to trigger the function of anothe rprotein,
Note: although with the sigma, its NOT a catalytic rxn
components of RNA Polymerase core?
alpha, aplhah, beta, beta prime, omega
What type of molecule is the RNA polymerase core?
pentahetero, because it has 5 different components and more than 1 different type
True or false, can any sigma factor bind to any promoter?
2 types of transcriptional termination?
Intrinsic and Rho dependant
Function of α (alpha) on RNA polymerase
recognizes and binds to UP elements using
their C-terminal domain
Function of β (Beta) on RNA Polymerase?
contains the polymerase activity
Function of β’ (Beta prime)?
binds and holds onto DNA
Location and function of ω (omega) on RNA Polymerase?
Location, at the bottom
ω stabilizes RNA polymerase structure
True or false, The type of sigma factor carried by the RNA
polymerase Holoenzyme determines which
promoter it can transcribe from
True
What are the 3 steps or transcription?
Initiation, elongation and termination
What is initiation?
binding of RNA polymerase to a promoter sequence
What is elongation?
sequential addition of NTPs using DNA as a template
What is termination?
dissociation of RNA polymerase
release of primary transcript from template
At what stag do we get rid of the sigma factor?
Abortive initiation (must break off sigma factor to go into elongation)
Open vs. closed complex for DNA
Closed: DNA is still attached to each other
Open: DNA is seperated from each other
3 Parts of initiation stage
- Loading stage
- Open and Closed complex stage
- Abortive Initiation stage
When does rho independant vs. dependant termination happen?
If high in GC bonds, rho independant,
if not, needs Rho to break it off
What type of molecule is Rho?
(hetero, hemo, how many?)
Homohexameric
