What is the main role of a molecular chaperone?
Assist in the folding of other proteins
Assist in the unfolding of other proteins
Assist in the assembly of other proteins
Assist in the disassembly of other proteins
Chaperone proteins are permanent parts of the proteins they fold
Why are chaperone proteins necessary?
Some proteins have complex folding pathways,
Some proteins are inherently soluble
Useful for multimeric assembly
So many proteins folding and interacting mean some need help
Name the role of the domain highlighted in bacterial trigger factor
PPIase domain
Interacts with polypeptide as it comes off the ribosome
Binds to L23 of the ribosome
The highlighted domain of Bacterial trigger factor binds to L23 of the ribosome
The bacterial ribosome and bacterial trigger factor form a complex, so the protein is folded as it comes off the ribosome
The N-domain of the bacterial trigger factor bind to what subunit of what size ribosome?
L23
L24
L25
50s
40s
30s
After the protein interacts with the T.F, it may interact with what proteins?
DNAK
DNAJ
DNAL
Gro-EL
Gro-ER
What percent of proteins can fold unaided after interacting with DNAK/J?
70%
65%
75%
10-15% of proteins need to use the lidded protein chaperone syastem
15-18% of proteins need further _ interactions?
Gro-El
Yeast has no trigger factor
In yeast, what protein folding complex interacts with the proteins first?
Nascent Polypeptide Associated Complex (NAC)
The Ribosome Associated Complex (RAC)
CCT
The RAC complex is made of which proteins?
Zuptin
Hsp40
SSZ
Hsp70
SSB is separated from the RAC but also chaperones protein folding
The NAC is made of A and B homologues
What is the role of the NAC?
Bind to nascent proteins and prevent aggregation
Binds to nascent proteins and degrades them based on protein concentrations in the cell
Binds to nascent proteins and folds them
Human cellss don't possess an NAC
Humans have an hRAC rather than an RAC
The human version of the RAC contains which two proteins?
MPP11
SSz
Hsp70L1
SSb
Name the lidded protein chaperone found in yeast and humans
Name the circled sets of cytoplasmic folding proteins
Hsp40/70- humans
Hsp40/70- yeast
SSa/YDJ1- yeast
Ssa/Ydj1- humans
Prefoldin