Combining crystallography and EPR: crystal and solution structures of the multidomain cochaperone DnaJ

Acta Crystallogr D Biol Crystallogr. 2013 Aug;69(Pt 8):1540-52. doi: 10.1107/S0907444913010640. Epub 2013 Jul 19.

Abstract

Hsp70 chaperones assist in a large variety of protein-folding processes in the cell. Crucial for these activities is the regulation of Hsp70 by Hsp40 cochaperones. DnaJ, the bacterial homologue of Hsp40, stimulates ATP hydrolysis by DnaK (Hsp70) and thus mediates capture of substrate protein, but is also known to possess chaperone activity of its own. The first structure of a complete functional dimeric DnaJ was determined and the mobility of its individual domains in solution was investigated. Crystal structures of the complete molecular cochaperone DnaJ from Thermus thermophilus comprising the J, GF and C-terminal domains and of the J and GF domains alone showed an ordered GF domain interacting with the J domain. Structure-based EPR spin-labelling studies as well as cross-linking results showed the existence of multiple states of DnaJ in solution with different arrangements of the various domains, which has implications for the function of DnaJ.

Keywords: cross-linking; crystal dehydration; electron paramagnetic resonance; hybrid structure determination; molecular chaperones; radiation-damage-induced phasing with anomalous scattering; single-wavelength anomalous diffraction.

MeSH terms

  • Amino Acid Substitution
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Crystallography, X-Ray
  • Electron Spin Resonance Spectroscopy
  • HSP40 Heat-Shock Proteins / chemistry*
  • HSP40 Heat-Shock Proteins / genetics
  • HSP40 Heat-Shock Proteins / metabolism
  • Methionine / genetics
  • Models, Molecular
  • Molecular Chaperones / chemistry
  • Protein Conformation
  • Protein Folding
  • Protein Structure, Tertiary
  • Thermus thermophilus / chemistry*

Substances

  • Bacterial Proteins
  • HSP40 Heat-Shock Proteins
  • Molecular Chaperones
  • Methionine

Associated data

  • PDB/4J7Z
  • PDB/4J80