Lecture 20

Question 1

Explain dimerization domains (2 parts)

Answer 1

The basic region contacts the DNA.

The Leu-zipper acts as the dimerization on the hydrophobic interface.

Question 2

Homodimers

Answer 2

2 proteins are the same

Question 3

Heterodimers

Answer 3

2 proteins are different

Question 4

Steroid receptor

Answer 4

Activation domain. Once the ligaand binds, tx factors are activated, and the structure change occurs.

Question 5

bHLH

Answer 5

basic protein HELIX-LOOP-HELIX

Question 6

What happens when 2 bHLHs bind?

Answer 6

dimerization occurs and the basic region binds to DNA

Question 7

What happens when a nonbasic HLH and bHLH bind?

Answer 7

the heterodimer can’t bind to the DNA

Question 8

What is required for RNA pol II to initiate transcription?

Answer 8

TFII X

Question 9

what sequence is at the initiator of POL II

Answer 9

Py(2) CA Py(5)

Question 10

Py’s are

Answer 10

pyrimidines

Question 11

Inr

Answer 11

Initiator

Question 12

DPE

Answer 12

downstream promoter element

in promoters w/o TATAA box

Question 13

2 types of core promoters

Answer 13

1. TATA

2. TATA less

Question 14

What does the core promoter for RNA pol II have

Answer 14

INR region

either a tATa or DPe

Question 15

TFIID

Answer 15

TBP (tata bind proteins)

TAFS (TBP associated factors)

Question 16

TBP

Answer 16

tata binding protein

Question 17

TAFS

Answer 17

TBP associated factors

Question 18

Where does TBP bind?

Answer 18

To the TATA box in the minor groove

Question 19

What happens when TBP binds?

Answer 19

The DNA bends giving more exposure

Question 20

Step 1 of pol II

Answer 20

TBP binds to TAFS to form TFIID

Question 21

Step 2 of pol II

Answer 21

TF2 F and TFII B bind

Question 22

Step 3 of pol II

Answer 22

TFII E comes in

Question 23

Step 4 of pol II

Answer 23

TF II H comes in with kinase activity and puts - charges on carboxy terminal domain

Question 24

Step 5 of pol II

Answer 24

Repulsion event causes transcription to begin and RNA pol II takes off

Question 25

What are required to melt DNA to allow the polymerase to move?

Answer 25

TF II E and H

Question 26

Explain the cycle of phosphorylation

Answer 26

1. Recruitment of RNA pol II
2. Phosphorylation recruits enzymes to cap 5’ end
3. Elongation occurs
4. Dephosphorylate and cycle continues

Question 27

What does the C terminal domian have that can be phoshorylated/

Answer 27

Threonine
Tyrosine
Serine

Question 28

Carboxy Terminal Domain

Answer 28

coordinates processing and export of tRNA from nucleus

Question 29

Which promoters do enhancers activate?

Answer 29

the ones nearest itself

Question 30

UAS

Answer 30

upstream activating sequence found in yeast

behaves like an enhancer but only works upstream

Question 31

What happens if the two molecules are catenated?

Answer 31

Transcription can occur! Enhancers can be made to work in trans as long as it’s constrained to be in proximity of the promoter.