Uncovering a region of heat shock protein 90 important for client binding in E. coli and chaperone function in yeast

Mol Cell. 2013 Feb 7;49(3):464-73. doi: 10.1016/j.molcel.2012.11.017. Epub 2012 Dec 20.


The heat shock protein 90 (Hsp90) family of heat shock proteins is an abundantly expressed and highly conserved family of ATP-dependent molecular chaperones. Hsp90 facilitates remodeling and activation of hundreds of proteins. In this study, we developed a screen to identify Hsp90-defective mutants in E. coli. The mutations obtained define a region incorporating residues from the middle and C-terminal domains of E. coli Hsp90. The mutant proteins are defective in chaperone activity and client binding in vitro. We constructed homologous mutations in S. cerevisiae Hsp82 and identified several that caused defects in chaperone activity in vivo and in vitro. However, the Hsp82 mutant proteins were less severely defective in client binding to a model substrate than the corresponding E. coli mutant proteins. Our results identify a region in Hsp90 important for client binding in E. coli Hsp90 and suggest an evolutionary divergence in the mechanism of client interaction by bacterial and yeast Hsp90.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / metabolism
  • Escherichia coli / cytology
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / metabolism*
  • HSP90 Heat-Shock Proteins / chemistry*
  • HSP90 Heat-Shock Proteins / metabolism*
  • Molecular Sequence Data
  • Mutant Proteins / chemistry
  • Mutant Proteins / metabolism
  • Mutation / genetics
  • Protein Binding
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Structure-Activity Relationship


  • Amino Acids
  • Escherichia coli Proteins
  • HSP82 protein, S cerevisiae
  • HSP90 Heat-Shock Proteins
  • HtpG protein, E coli
  • Mutant Proteins
  • Saccharomyces cerevisiae Proteins