Lecture, RNA Poly parts

Question 1

3 steps for transcription for bacterial gene

Answer 1

Initiation, elongation, termination

Question 2

sigma factor purpose?

Answer 2

Assists RNA polymerase to bind to specific promoters, (remember, NOT done through a chem rxn!!)

Question 3

Holoenzyme meaning?

Answer 3

An protein needed to trigger the function of anothe rprotein,
Note: although with the sigma, its NOT a catalytic rxn

Question 4

components of RNA Polymerase core?

Answer 4

alpha, aplhah, beta, beta prime, omega

Question 5

What type of molecule is the RNA polymerase core?

Answer 5

pentahetero, because it has 5 different components and more than 1 different type

Question 6

True or false, can any sigma factor bind to any promoter?

Question 7

2 types of transcriptional termination?

Answer 7

Intrinsic and Rho dependant

Question 8

Function of α (alpha) on RNA polymerase

Answer 8

recognizes and binds to UP elements using
their C-terminal domain

Question 9

Function of β (Beta) on RNA Polymerase?

Answer 9

contains the polymerase activity

Question 10

Function of β’ (Beta prime)?

Answer 10

binds and holds onto DNA

Question 11

Location and function of ω (omega) on RNA Polymerase?

Answer 11

Location, at the bottom
ω stabilizes RNA polymerase structure

Question 12

True or false, The type of sigma factor carried by the RNA
polymerase Holoenzyme determines which
promoter it can transcribe from

Answer 12

True

Question 13

What are the 3 steps or transcription?

Answer 13

Initiation, elongation and termination

Question 14

What is initiation?

Answer 14

binding of RNA polymerase to a promoter sequence

Question 15

What is elongation?

Answer 15

sequential addition of NTPs using DNA as a template

Question 16

What is termination?

Answer 16

dissociation of RNA polymerase
release of primary transcript from template

Question 17

At what stag do we get rid of the sigma factor?

Answer 17

Abortive initiation (must break off sigma factor to go into elongation)

Question 18

Open vs. closed complex for DNA

Answer 18

Closed: DNA is still attached to each other
Open: DNA is seperated from each other

Question 19

3 Parts of initiation stage

Answer 19

1. Loading stage
2. Open and Closed complex stage
3. Abortive Initiation stage

Question 20

When does rho independant vs. dependant termination happen?

Answer 20

If high in GC bonds, rho independant,
if not, needs Rho to break it off

Question 21

What type of molecule is Rho?
(hetero, hemo, how many?)

Answer 21

Homohexameric