energy metabolism enzymes
in nucleus protect nucleus proteins
target very damaged proteins to proteosome degredation
Structure
primary:ATP binding + ATPase domain44kDa---linker----protein binding domain13kDa----lid 10kDa
high affinity for protein binding in ADP binding form
low affinity for protein binding in ATP binding form
hsp70-ATP associates with a protein's short hydrophobic segments, ATP hydrolysis after binding, and hsp70-ADP shields the protein from aggregation
just like DNAK and with out assist of DNAJ
it binds directly to the misfolded protein, and hydrolysis it self ATP
Further speeding ATP hydrolysis are the so-called J-domain cochaperones: primarily Hsp40 in eukaryotes,
