transcription (factors and regulation)

Question 1

eukarutoic RNA pol 2

requires alot of TF but cannot initiate transcription without

Answer 1

the sigma factor

Question 2

eukaryotic promoters

what promoters are there and where

Answer 2

enchancer at -1000
USE (upstream sequence element) at -100
TATA at -35
initiator at +1

Question 3

general TF are

Answer 3

common to all promoters

Question 4

core promoters and TF at TATA what happens

5 POINTS

Answer 4

general TF TF2 for pol 2 binds to TATA
using TBP (TATA binding protein) which is in TF2D
once bound recruits TF2A and TF2B
then pol 2 binds
allowing TF2H, E AND F TO BIND

Question 5

TF2H how many subunits and what is its activity

Answer 5

9 subunts
ATPase
helicase
protein kinase

Question 6

what does Tf2H do

Answer 6

phosphorylates the C terminus of RNA pol at Cyr
which helps for post transcriptional modification
causes conformational change and tightening grip

Question 7

Tf3 what does it do

Answer 7

recognises DPE (downstream promoter)
which is AGAC
at +28 - +32
helps start trancription

Question 8

PIC what is it

what does it cause

Answer 8

pre initiation complex

causes very low levels of trancription

Question 9

upstream sequence elements

2 promoters upsteam what are they and where

Answer 9

GC box at 40-100bp upstream

CAAT box also at 40- 100 bp

Question 10

what do the 2 upstream promoters bind to and with what

Answer 10

GC box has GGGCGG sequence that TF SP1 binds to

CAAT box is itself the TF are CTF or NF1

Question 11

zinc fingers

what do they contain

Answer 11

a loop of 23aa

linker between fingers is 7-8aa

Question 12

zinc fingers binds and causes activation how

Answer 12

induces conformational change forming dimers
translocates into nucleus
binds to specific sequence in promotr of gene and activates expression

Question 13

helix turn helix (homeodomain)

facts about it

Answer 13

60 aa
contains 3 alpha helices
1 and 2 point away from the DNA
plays a major role in early development
homeodomain is highly conserved throughout evolution

Question 14

basic binding proteins what do they have to do

Answer 14

they have to be a dimer because they cant bind to dna alone

Question 15

leucine zipper

facts about it

Answer 15

amphipathic helix
leucine found in every 7th aa
leucine from 1 molecules interdigitates with another

Question 16

herterodimerization

Answer 16

leucine -leucine interaction

Question 17

how do TF activation domains work

2 answers

Answer 17

1) direct interaction with the PIC

2) through the recruitment of other cofactors

Question 18

1) direct interaction with the PIC

what does it consist of

Answer 18

SP1

and ER

Question 19

2) through the recruitment of other cofactors

what does it consist of

Answer 19

interactions with PIC

opening loosening chromatin structure

Question 20

why are co activators used

and how

Answer 20

to modify histones

by using HAT

Question 21

what is HAT and what does it do

5 points

Answer 21

histone acetylase
acetylates n terminus tail lysine of histone
neutralising +ve charge
opens up DNA
allows TF to get in and also RNA pol

Question 22

MAD what dies it do

Answer 22

it removes the acetylate group that was placed there by HAT and closes DNA