Pregunta 1
Pregunta
Chaperonins are for nascent proteins that don't fold independently or interact with other cytosolic chaperones
Pregunta 2
Pregunta
To what is the arrow pointing on the Gro-El monomer?
Pregunta 3
Pregunta
How many monomers make up Gro-El?
Respuesta
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14- 7 in each layer
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12- 6 in each layer
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10- 5 in each layer
Pregunta 4
Pregunta
Gro-Es is made of 7 monomers
Pregunta 5
Pregunta
Why does Gro-Es bind to close the cavity?
Respuesta
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Creates a space away from crowded cytosol for protein binding
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Creates a highly acidic environment for proteins to fold in
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Allows protein to fold in highly saline environment
Pregunta 6
Pregunta
ATP & Gro-Es bind at separate points in the protein folding cycle
Pregunta 7
Pregunta
The nascent protein will bind at the monomer level _ side with ADP and Gro-Es bound
Pregunta 8
Pregunta
Once Gro-Es and ATP are bound, the protein refolds for _ seconds whilst the ATP is hydrolysed
Pregunta 9
Pregunta
When the protein has folded properly, what happens?
Respuesta
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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
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Gro-Es dissociates, releasing the folded protein
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The ADP is released and replaced with ATP
Pregunta 10
Pregunta
The CCT and Gro-El cycles are basically the same, but Gro-El has flexible extensions that CCT does not
Pregunta 11
Pregunta
What is bacterial homologue of the Hsp100 family?
Pregunta 12
Pregunta
Hsp100 and its bacterial homologue are hexamers
Pregunta 13
Pregunta
Clp100 and its bacterial homologue do what?
Pregunta 14
Pregunta
What is the difference between Class 1 & Class 2 Hsp100 proteins?
Pregunta 15
Pregunta
How do you tell apart Class 1 and Class 2
Respuesta
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Class 1 has 2 ATPase sites, Class 2 has 1
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Class 1 has 1 ATPase site, Class 2 has 2
Pregunta 16
Pregunta
Hsp100's consist of one/two sets of hexamers
Pregunta 17
Pregunta
The ATP is hydrolysed in Hsp100's/Clp proteins to allow what?
Respuesta
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To drive conformational changes in aromatic loops that interact with the substrate
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To provide energy to break the peptide bonds in the protein to be unfolded
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To provide energy to posh apart poorly stacked peptides
Pregunta 18
Pregunta
When ClpA and ClpP interact, what is the role of the supercomplex?
Pregunta 19
Pregunta
Hsp90 chaperones are required for what?
Respuesta
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High temperature growth
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High salinity growth
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High pH growth
Pregunta 20
Pregunta
Hsp90 are ATP dependent monomers
Pregunta 21
Pregunta
What is found on the N-terminus of a Hsp90 protein?
Respuesta
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ATP binding site
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Substrate binding domain
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Dimerisation domain
Pregunta 22
Pregunta
The dimerisation domain of Hsp90 occurs at the C terminus
Pregunta 23
Pregunta
ATPase inhibitors of Hsp90 target which part of the protein?
Respuesta
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N terminus
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C terminus
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Middle
Pregunta 24
Pregunta
The binding of ATP causes the ATP 'lid' to close and the dimer to split
Pregunta 25
Pregunta
Name the conformational changes that occur after ATP binds
Respuesta
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N-terminals undergo Beta strand exchange
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N-terminals undergo Alpha helix exchange
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Rotation of N domain (relative to middle) to allow meeting of dimerisation domains
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Rotation of C domain (relative to middle) to allow meeting of dimerisation domains
Pregunta 26
Pregunta
What is the role of the core domain of Hsp90 (with regards to the ATPase)
Respuesta
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It's flexible enough that it completes the dimerisation site and allows ATP hydrolysis to occur
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It's flexible enough that it completes the ATPase site and allows ATP hydrolysis to occur
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Interacting with the gamma phosphate of ATP
Pregunta 27
Pregunta
The conformational changes of Hsp90 are thought to be brought about by client proteins
Pregunta 28
Pregunta
cd37/p50 inhibit Hsp90 by what process?
Pregunta 29
Pregunta
Sti/HOP bind to the N-terminal of Hsp90 & Hsp70, binding them together as a potent inhibitor
Pregunta 30
Pregunta
Aha activates Hsp90 how?
Respuesta
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Activates ATPase activity by promoting open state of of catalytic loop
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Causing N-terminal alignment for dimerisation
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Physically holding the active site open
Pregunta 31
Pregunta
Spa1 both inhibits and stimulates ATPase activity, leading to an overall slowing of ATPase in Hsp90
Pregunta 32
Pregunta
How does Sba activate ATPase activity?
Respuesta
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Interacts with the middle domain of Hsp90 and modulates the catalytic loop of this domain
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Increases the affinity of the dimerisation sites for each other, completing the ATPase sites more stably
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Increases the affinity for the binding site for ATP
Pregunta 33
Pregunta
Hsp90 can be used to activate steroid receptors and kinases