Allosteric opening of the polypeptide-binding site when an Hsp70 binds ATP

Nat Struct Mol Biol. 2013 Jul;20(7):900-7. doi: 10.1038/nsmb.2583. Epub 2013 May 26.


The 70-kilodalton (kDa) heat-shock proteins (Hsp70s) are ubiquitous molecular chaperones essential for cellular protein folding and proteostasis. Each Hsp70 has two functional domains: a nucleotide-binding domain (NBD), which binds and hydrolyzes ATP, and a substrate-binding domain (SBD), which binds extended polypeptides. NBD and SBD interact little when in the presence of ADP; however, ATP binding allosterically couples the polypeptide- and ATP-binding sites. ATP binding promotes polypeptide release; polypeptide rebinding stimulates ATP hydrolysis. This allosteric coupling is poorly understood. Here we present the crystal structure of an intact ATP-bound Hsp70 from Escherichia coli at 1.96-Å resolution. The ATP-bound NBD adopts a unique conformation, forming extensive interfaces with an SBD that has changed radically, having its α-helical lid displaced and the polypeptide-binding channel of its β-subdomain restructured. These conformational changes, together with our biochemical assays, provide a structural explanation for allosteric coupling in Hsp70 activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphate / metabolism*
  • Allosteric Regulation
  • Amino Acid Sequence
  • Binding Sites
  • Conserved Sequence
  • Crystallography, X-Ray
  • Dimerization
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • HSP70 Heat-Shock Proteins / chemistry*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism
  • Hydrogen Bonding
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation, Missense
  • Peptides / metabolism
  • Protein Binding
  • Protein Conformation
  • Protein Folding
  • Protein Interaction Mapping
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Escherichia coli Proteins
  • HSP70 Heat-Shock Proteins
  • Peptides
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Adenosine Triphosphate
  • Adenosine Triphosphatases
  • dnaK protein, E coli
  • SSA1 protein, S cerevisiae

Associated data

  • PDB/4JN4
  • PDB/4JNE
  • PDB/4JNF