Send to

Choose Destination
Mol Microbiol. 2001 Jan;39(1):199-210.

Chaperone function of FkpA, a heat shock prolyl isomerase, in the periplasm of Escherichia coli.

Author information

Unité de Programmation Moléculaire et de Toxicologie Génétique/CNRS-URA1444, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France.


The nature of molecular chaperones in the periplasm of Escherichia coli that assist newly translocated proteins to reach their native state has remained poorly defined. Here, we show that FkpA, a heat shock periplasmic peptidyl-prolyl cis/trans isomerase (PPIase), suppresses the formation of inclusion bodies from a defective-folding variant of the maltose-binding protein, MalE31. This chaperone-like activity of FkpA, which is independent of its PPIase activity, requires a full-length structure of the protein. In vitro, FkpA does not catalyse a slow rate-limiting step in the refolding of MalE31, but prevents its aggregation at stoichiometric amounts and promotes the reactivation of denaturated citrate synthase. We propose that FkpA functions as a chaperone for envelope proteins in the bacterial periplasm.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center