Questão 1
Questão
Which of the following is not a role of the DNAK/Hsp70 superfamily?
Responda
-
Stabilise nascent polypeptides
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Repaor heat shocked proteins
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Preserve folding proteins
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Protein transport
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Protein degredation
Questão 2
Questão
Hsp70s (unlike DNAK's) do not require chaperones
Questão 3
Questão
What is the role of DNAJ/Hsp40 when combined with DNAK/Hsp70
Questão 4
Questão
DNAK/Hsp70 need NEF's in order to function
Questão 5
Questão
Where is the Hsp70/DNAK binding domain for ATP?
Responda
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N-terminus
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Core
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C- terminus
Questão 6
Questão
Name the subdomains of the ATPase found in DNAK/Hsp70
Questão 7
Questão
What increases the ATPase activity of the ATP binding domain?
Questão 8
Questão
The core substrate binding domain has an affinity for what?
Responda
-
Neutral, hydrophobic aa
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Acidic, polar aa
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Basic, polar aa
Questão 9
Questão
The C-terminus of DNAK/Hsp 70 acts as a 'lid' for the protein
Questão 10
Questão
When ATP is hydrolysed in DNAK/Hsp70, where does the C-terminus bind to?
Responda
-
The N-terminus
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The core
-
It doesn't move at all
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Over the bound substrate
Questão 11
Questão
Without the assistance of DNAJ/Hsp40, the ATPase in DNAK/Hsp70 works too slowly for the C-terminus to trap the bound substrate
Questão 12
Questão
Hsp70/DNAK's preferred binding pattern is 15 aa long
Questão 13
Questão
What are the 'Flanking' residues (1-4, 9-13) of Hsp70's preferred binding site made of?
Questão 14
Questão
The preferred residue for the -Core- of Hsp70's preferred binding site is Valine
Questão 15
Questão
What other residues can make up the 'core' of the preferred binding site/
Questão 16
Questão
How does this 'Preferred Binding Patter' for Hsp70 help direct the protein?
Responda
-
In properly folded proteins, the hydrophobic stretch is hidden, and so only nascent/denatured proteins have the exposed residues for Hsp70 to bind to
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In nascent/denatured proteins, these hydrophobic residues will be added by Hsp40, so it can recognise them
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Stretches with the core residues are removed during protein folding, so only nascent polypeptides have them
Questão 17
Questão
What is the role of the J domain in a Hsp40?
Responda
-
Contain the HPD peptide needed to boost Hsp40's ATPase
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Gly/Phe rich linker for positioning
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Dimerisation domain
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Zn+ 'finger' for substrate binding
Questão 18
Questão
The role of the Gly/Phe rich linker does what?
Responda
-
Makes DNAJ/Hsp40 flexible enough to bind to its respective protein
-
Makes DNAJ/Hsp40 a more effective ATPase
-
Allows DNAJ/Hsp40 to locate its respective DNAK/Hsp70
Questão 19
Questão
The Zinc 'Finger' is for substrate binding
Questão 20
Questão
Which amino acids make up the HPD domain?
Responda
-
Histadine
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Proline
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Aspartate
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Leucine
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Glycine
Questão 21
Questão
The Znc finger of DNAJ/Hsp40 can interact with the nascent polypeptide and bring it to the DNAK/Hsp70
Questão 22
Questão
What is the sequence of the Zinc 'finger'?
Responda
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CXXCXGXG
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GXXGXCXC
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GXXCXGXC
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CXXGXCXG
Questão 23
Questão
The C-terminus of Hsp40 is for tetramerisation
Questão 24
Questão
What effect does the GEF factor binding have on the Hsp70/Hsp40 complex?
Questão 25
Questão
When the substrate & Hsp40 bind to Hsp70, the GEF factor also binds
Questão 26
Questão
How is the nascent polypeptide transferred from the DNAJ site to the DNK site?
Responda
-
The G/F domain is flexible enough to bind to the DNAK site and pull it in for transfer
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The J domain is pulled like a thread through the ATPase, bringing the two sites close enough together for transfer
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The dimerisation of the DNAJ pulls the two sites close together
Questão 27
Questão
In which of the following is Prefoldin found?
Responda
-
Archea
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Prokaryotes
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Eukaryotes
Questão 28
Questão
Prefoldin can act as a substitute for Hsp70 if the organsim doesn't have the latter
Questão 29
Questão
Prefoldin is ATP dependent
Questão 30
Questão
Prefolding is a...
Questão 31
Questão
What is the role of Preofoldin in Archea?
Responda
-
Captures nascent polypeptides and binds them to Gro-El
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Captures nascent polypeptides and binds them to CCT
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Captures nascent polypeptides and binds them to SSA
Questão 32
Questão
In Eukaryotes, prefoldin might be specific for the folding of what?
Responda
-
Actin/tubulin
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CCT
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Hsp40
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Hsp70
Questão 33
Questão
In archea there are 6 Prefoldin genes (Grim1-6) in Eukaryotes there are 2 (Gimalpha and Gimbeta)
Questão 34
Questão
Which of the following describe Prefoldin
Questão 35
Questão
There are 3.5 amino acid residues per helical turn of the coiled coil helices in Prefoldin (not 3.6)
Questão 36
Questão
The subunits forming the dimerisation interface of the below molecule are what?
Questão 37
Questão
Where do the non-native proteins bind to Prefoldin?
Responda
-
Exposed hydrophobic residues in the distal ends of the 'tentacle'
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Exposed hydrophobic residues in the proximal ends of the 'tentacle'
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Exposed hydrophobic residues at the top of the 'tentacle'