Exam 1 - Dr. White

Question 1

Helix - turn - helix proteins

Answer 1

• simplest one
• 2 alphas connecged by short aa chain = turn
• longer = recognition
• side chains recognize DNA motif
• can form DIMERS

Question 2

zinc finger proteins

Answer 2

-includes Zn atom
- alpha - helix binds to major groove
- found in tandem clusters
- stabilize interactions with DNA

Question 2

Leucine zipper proteins

Answer 2

• 2 alpha helical for dimer
  -grabs DNA like clothespin
• hydrophobic aa interaction (leucine) creates dimer EVERY 7 aa down

Question 3

helix-loop-helix proteins

Answer 3

-short alpha chain connected by a loop to second longer alpha chain
- flexible

Question 4

what is an example of Zinc finger

Answer 4

Hemolytic anemia caused by fragile , spherical RBC

• caused by: a mutation in alpha, beta spectin, ankyrin or KLF1 (TF that turns genes on)

Question 5

what are the mechanisms that help a gene regulatory protein control gene transcription?

Answer 5

• includes promotor, general TF, regulatory sequence and regulatory proteins that turn gene on or off

Question 6

what is the mediator protein complex?

Answer 6

allows assembly at promotor loops to allow protein interaction, allows mRNA to be transcribed

Question 7

what are the 4 gene activators? (turn gene off)

Answer 7

1 - Nucleosome remodeling
2 - nucleosome removal
3 - histone replacement
4 - histone modification

Question 8

what are the 6 gene repressors

Answer 8

1 - competitive inhibition
2 - masking activation
3 - direct inhibition
4 - chromatin remodeling complex
5 - histone deacetylace
6 - methyl transferace

Question 9

competitive inhibitor

Answer 9

activator and repressor compete for the same binding site

Question 10

masking activation

Answer 10

both the repressor and activator bind to DNA but repressor does not allow activation

Question 11

direct inhibition

Answer 11

repressor binds to DNA and blocks TF assembly

Question 12

chromatin remodeling compkex

Answer 12

repressor recruits to return promotor to pre-transcription phase

Question 13

histone deacytlyation

Answer 13

harder to open up DNA , cant remove nucleosomes

Question 14

methyl transferase

Answer 14

proteins which maintain chromatin in transcriptionally silent form

Question 15

alpha globin like chains

Answer 15

(zeta) - embryotic
(alpha) - adult

Question 16

beta globin like chains

Answer 16

(epsilon) - embryonic
(gamma) - fetal
(delta) - adult
(beta) - adult