7KRV

Stimulating state of disulfide-bridged Hsp70 DnaK

Summary for 7KRV

• Entry DOI: 10.2210/pdb7krv/pdb
• Related: 7KRU
• Descriptor: Chaperone protein DnaK fused with substrate peptide, SULFATE ION, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: molecular chaperone, hsp70, protein folding, chaperone
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 2
• Total formula weight: 121406.51

Authors

Wang, W.,Hendrickson, W.A. (deposition date: 2020-11-20, release date: 2021-09-15, Last modification date: 2024-11-06)

Primary citation

Wang, W.,Liu, Q.,Liu, Q.,Hendrickson, W.A.
Conformational equilibria in allosteric control of Hsp70 chaperones.
Mol.Cell, 81:3919-, 2021

PubMed Abstract: Heat-shock proteins of 70 kDa (Hsp70s) are vital for all life and are notably important in protein folding. Hsp70s use ATP binding and hydrolysis at a nucleotide-binding domain (NBD) to control the binding and release of client polypeptides at a substrate-binding domain (SBD); however, the mechanistic basis for this allostery has been elusive. Here, we first characterize biochemical properties of selected domain-interface mutants in bacterial Hsp70 DnaK. We then develop a theoretical model for allosteric equilibria among Hsp70 conformational states to explain the observations: a restraining state, Hsp70-ATP, restricts ATP hydrolysis and binds peptides poorly, whereas a stimulating state, Hsp70-ATP, hydrolyzes ATP rapidly and has high intrinsic substrate affinity but rapid binding kinetics. We support this model for allosteric regulation with DnaK structures obtained in the postulated stimulating state S with biochemical tests of the S-state interface and with improved peptide-binding-site definition in an R-state structure.

PubMed: 34453889
DOI: 10.1016/j.molcel.2021.07.039

Experimental method

X-RAY DIFFRACTION (1.92 Å)