BIOC 212 Lecture Notes - Dna-Binding Domain, Hsf1, Hspa8
Document Summary
How peptide is bound, where polypeptide substrate is folded. Lbd w/out hormone is unstable, hydrophobic gap where hormone should be, cannot form stable folded state. Lbd is dependent on chaperones all the time. Dnaj binds to substrate, activates hsc70 which also binds to substrate. Lets go hsc70, hsp90 is still there, fkbp52 replaces hop on hsp90, together work on lbd, p23 stabilizes closed atp bound form of hsp90. No hormone, keep on cycling until hormone is available. For humans, heat shock is anything above 37 degrees c. Even after cells are back to 37 degrees, translation is still inhibited (problem with unfolded proteins, don"t want to make more) Only when hsf1 is a trimer, active form, can it recognize hse promoters. After heat shock, lots of unfolded proteins, a lot of hydrophobicity. More hsf1 that is free and can bind excess hsp90. Some side chains are more reactive than others, catalyzed by enzymes.
