Solution conformation of wild-type E. coli Hsp70 (DnaK) chaperone complexed with ADP and substrate

Proc Natl Acad Sci U S A. 2009 May 26;106(21):8471-6. doi: 10.1073/pnas.0903503106. Epub 2009 May 13.

Abstract

DnaK is the canonical Hsp70 molecular chaperone protein from Escherichia coli. Like other Hsp70s, DnaK comprises two main domains: a 44-kDa N-terminal nucleotide-binding domain (NBD) that contains ATPase activity, and a 25-kDa substrate-binding domain (SBD) that harbors the substrate-binding site. Here, we report an experimental structure for wild-type, full-length DnaK, complexed with the peptide NRLLLTG and with ADP. It was obtained in aqueous solution by using NMR residual dipolar coupling and spin labeling methods and is based on available crystal structures for the isolated NBD and SBD. By using dynamics methods, we determine that the NBD and SBD are loosely linked and can move in cones of +/-35 degrees with respect to each other. The linker region between the domains is a dynamic random coil. Nevertheless, an average structure can be defined. This structure places the SBD in close proximity of subdomain IA of the NBD and suggests that the SBD collides with the NBD at this area to establish allosteric communication.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenosine Diphosphate / chemistry*
  • Adenosine Diphosphate / metabolism*
  • Escherichia coli / chemistry*
  • 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*
  • Models, Molecular
  • Mutation / genetics
  • Protein Structure, Tertiary
  • Structural Homology, Protein
  • Substrate Specificity
  • Time Factors

Substances

  • Escherichia coli Proteins
  • HSP70 Heat-Shock Proteins
  • Adenosine Diphosphate
  • dnaK protein, E coli

Associated data

  • PDB/2KHO