Chaperonins

Description

Structural Basis for Biological Function (Protein Folding) Quiz on Chaperonins, created by gina_evans0312 on 20/12/2013.
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Quiz by gina_evans0312, updated more than 1 year ago
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Created by gina_evans0312 almost 11 years ago
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Resource summary

Question 1

Question
Chaperonins are for nascent proteins that don't fold independently or interact with other cytosolic chaperones
Answer
  • True
  • False

Question 2

Question
To what is the arrow pointing on the Gro-El monomer?
Answer
  • Apical substrate binding site
  • Hinge
  • ATP binding site

Question 3

Question
How many monomers make up Gro-El?
Answer
  • 14- 7 in each layer
  • 12- 6 in each layer
  • 10- 5 in each layer

Question 4

Question
Gro-Es is made of 7 monomers
Answer
  • True
  • False

Question 5

Question
Why does Gro-Es bind to close the cavity?
Answer
  • Creates a space away from crowded cytosol for protein binding
  • Creates a highly acidic environment for proteins to fold in
  • Allows protein to fold in highly saline environment

Question 6

Question
ATP & Gro-Es bind at separate points in the protein folding cycle
Answer
  • True
  • False

Question 7

Question
The nascent protein will bind at the monomer level _ side with ADP and Gro-Es bound
Answer
  • At the same
  • Opposite

Question 8

Question
Once Gro-Es and ATP are bound, the protein refolds for _ seconds whilst the ATP is hydrolysed
Answer
  • 10-15
  • 15-20
  • 20-25

Question 9

Question
When the protein has folded properly, what happens?
Answer
  • A nascent polypeptide binds to the end opposite the Gro-Es and ADP, causing the cycle to repeat itself at the other end of the protein
  • Gro-Es dissociates, releasing the folded protein
  • The ADP is released and replaced with ATP

Question 10

Question
The CCT and Gro-El cycles are basically the same, but Gro-El has flexible extensions that CCT does not
Answer
  • True
  • False

Question 11

Question
What is bacterial homologue of the Hsp100 family?
Answer
  • Clp
  • Clr
  • Cld

Question 12

Question
Hsp100 and its bacterial homologue are hexamers
Answer
  • True
  • False

Question 13

Question
Clp100 and its bacterial homologue do what?
Answer
  • Unfold proteins in the presence of ATP
  • Fold proteins in the presence of ATP

Question 14

Question
What is the difference between Class 1 & Class 2 Hsp100 proteins?
Answer
  • Class 1- Protein degredation Class 2- Protein disaggregation and refolding
  • Class 1- Protein disaggregation and refolding Class 2- Protein degredation

Question 15

Question
How do you tell apart Class 1 and Class 2
Answer
  • Class 1 has 2 ATPase sites, Class 2 has 1
  • Class 1 has 1 ATPase site, Class 2 has 2

Question 16

Question
Hsp100's consist of one/two sets of hexamers
Answer
  • True
  • False

Question 17

Question
The ATP is hydrolysed in Hsp100's/Clp proteins to allow what?
Answer
  • To drive conformational changes in aromatic loops that interact with the substrate
  • To provide energy to break the peptide bonds in the protein to be unfolded
  • To provide energy to posh apart poorly stacked peptides

Question 18

Question
When ClpA and ClpP interact, what is the role of the supercomplex?
Answer
  • Unravel denatured protein
  • Refold it
  • Degrade it

Question 19

Question
Hsp90 chaperones are required for what?
Answer
  • High temperature growth
  • High salinity growth
  • High pH growth

Question 20

Question
Hsp90 are ATP dependent monomers
Answer
  • True
  • False

Question 21

Question
What is found on the N-terminus of a Hsp90 protein?
Answer
  • ATP binding site
  • Substrate binding domain
  • Dimerisation domain

Question 22

Question
The dimerisation domain of Hsp90 occurs at the C terminus
Answer
  • True
  • False

Question 23

Question
ATPase inhibitors of Hsp90 target which part of the protein?
Answer
  • N terminus
  • C terminus
  • Middle

Question 24

Question
The binding of ATP causes the ATP 'lid' to close and the dimer to split
Answer
  • True
  • False

Question 25

Question
Name the conformational changes that occur after ATP binds
Answer
  • N-terminals undergo Beta strand exchange
  • N-terminals undergo Alpha helix exchange
  • Rotation of N domain (relative to middle) to allow meeting of dimerisation domains
  • Rotation of C domain (relative to middle) to allow meeting of dimerisation domains

Question 26

Question
What is the role of the core domain of Hsp90 (with regards to the ATPase)
Answer
  • It's flexible enough that it completes the dimerisation site and allows ATP hydrolysis to occur
  • It's flexible enough that it completes the ATPase site and allows ATP hydrolysis to occur
  • Interacting with the gamma phosphate of ATP

Question 27

Question
The conformational changes of Hsp90 are thought to be brought about by client proteins
Answer
  • True
  • False

Question 28

Question
cd37/p50 inhibit Hsp90 by what process?
Answer
  • Binding it to Hsp70
  • Preventing N-terminal dimerisation
  • Phosphorylation of Hsp90

Question 29

Question
Sti/HOP bind to the N-terminal of Hsp90 & Hsp70, binding them together as a potent inhibitor
Answer
  • True
  • False

Question 30

Question
Aha activates Hsp90 how?
Answer
  • Activates ATPase activity by promoting open state of of catalytic loop
  • Causing N-terminal alignment for dimerisation
  • Physically holding the active site open

Question 31

Question
Spa1 both inhibits and stimulates ATPase activity, leading to an overall slowing of ATPase in Hsp90
Answer
  • True
  • False

Question 32

Question
How does Sba activate ATPase activity?
Answer
  • Interacts with the middle domain of Hsp90 and modulates the catalytic loop of this domain
  • Increases the affinity of the dimerisation sites for each other, completing the ATPase sites more stably
  • Increases the affinity for the binding site for ATP

Question 33

Question
Hsp90 can be used to activate steroid receptors and kinases
Answer
  • True
  • False
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