A new native EcHsp31 structure suggests a key role of structural flexibility for chaperone function

Paulene M. Quigley, Konstantin Korotkov, François Baneyx, Wim G.J. Hol

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Heat shock proteins and proteases play a crucial role in cell survival under conditions of environmental stress. The heat shock protein Hsp31, produced by gene hchA at elevated temperatures in Escherichia coli, is a homodimeric protein consisting of a large A domain and a smaller P domain connected by a linker. Two catalytic triads are present per dimer, with the Cys and His contributed by the A domain and an Asp by the P domain. A new crystal Form II confirms the dimer and catalytic triad arrangement seen in the earlier crystal Form I. In addition, several loops exhibit increased flexibility compared to the previous Hsp31 dimer structure. In particular, loops D2 and D3 are intriguing because their mobility leads to the exposure of a sizable hydrophobic patch made up by surface areas of both subunits near the dimer interface. The residues creating this hydrophobic surface are completely conserved in the Hsp31 family. At the same time, access to the catalytic triad is increased. These observations lead to the hypothesis for the functioning of Hsp31 wherein loops D2 and D3 play a key role: first, at elevated temperatures, by becoming mobile and uncovering a large hydrophobic area that helps in binding to client proteins, and second, by removing the client protein from the hydrophobic patch when the temperature decreases and the loops adopt their low-temperature positions at the Hsp31 surface. The proposed mode of action of flexible loops in the functioning of Hsp31 may be a general principle employed by other chaperones.

Original languageEnglish
Pages (from-to)269-277
Number of pages9
JournalProtein Science
Issue number1
StatePublished - Jan 2004


  • Chaperone
  • DJ-1
  • Heat shock protein
  • PfPI family
  • ThiJ family
  • hchA

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'A new native EcHsp31 structure suggests a key role of structural flexibility for chaperone function'. Together they form a unique fingerprint.

Cite this