Chaperone activation and client binding of a 2-cysteine peroxiredoxin

Nat Commun. 2019 Feb 8;10(1):659. doi: 10.1038/s41467-019-08565-8.


Many 2-Cys-peroxiredoxins (2-Cys-Prxs) are dual-function proteins, either acting as peroxidases under non-stress conditions or as chaperones during stress. The mechanism by which 2-Cys-Prxs switch functions remains to be defined. Our work focuses on Leishmania infantum mitochondrial 2-Cys-Prx, whose reduced, decameric subpopulation adopts chaperone function during heat shock, an activity that facilitates the transition from insects to warm-blooded host environments. Here, we have solved the cryo-EM structure of mTXNPx in complex with a thermally unfolded client protein, and revealed that the flexible N-termini of mTXNPx form a well-resolved central belt that contacts and encapsulates the unstructured client protein in the center of the decamer ring. In vivo and in vitro cross-linking studies provide further support for these interactions, and demonstrate that mTXNPx decamers undergo temperature-dependent structural rearrangements specifically at the dimer-dimer interfaces. These structural changes appear crucial for exposing chaperone-client binding sites that are buried in the peroxidase-active protein.

Publication types

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

MeSH terms

  • Cryoelectron Microscopy
  • Cysteine / metabolism*
  • Leishmania infantum / metabolism
  • Molecular Chaperones / metabolism*
  • Peroxiredoxins / metabolism*
  • Protein Binding
  • Protein Folding


  • Molecular Chaperones
  • Peroxiredoxins
  • Cysteine