PMID:12021775

From EcoliWiki
Jump to navigation Jump to search
Citation

Schiene-Fischer, C, Habazettl, J, Schmid, FX and Fischer, G (2002) The hsp70 chaperone DnaK is a secondary amide peptide bond cis-trans isomerase. Nat. Struct. Biol. 9:419-24

Abstract

Peptidyl prolyl cis-trans isomerases can enzymatically assist protein folding, but these enzymes exclusively target the peptide bond preceding proline residues. Here we report the identification of the Hsp70 chaperone DnaK as the first member of a novel enzyme class of secondary amide peptide bond cis-trans isomerases (APIases). APIases selectively accelerate the cis-trans isomerization of nonprolyl peptide bonds. Results from independent experiments support the APIase activity of DnaK: (i) exchange crosspeaks between the cis-trans conformers appear in 2D (1)H NMR exchange spectra of oligopeptides (ii) the rate constants for the cis-trans isomerization of various dipeptides increase and (iii) refolding of the RNase T1 P39A variant is catalyzed. The APIase activity shows both regio and stereo selectivity and is stimulated two-fold in the presence of the complete DnaK/GrpE/DnaJ/ATP refolding system. Moreover, known DnaK-binding oligopeptides simultaneously affect the APIase activity of DnaK and the refolding yield of denatured firefly luciferase in the presence of DnaK/GrpE/DnaJ/ATP. These results suggest a new role for the chaperone as a regioselective catalyst for bond rotation in polypeptides.

Links

PubMed Online version:10.1038/nsb804

Keywords

Adenosine Triphosphate/metabolism; Amides/chemistry; Amides/metabolism; Animals; Bacterial Proteins/metabolism; Beetles; Binding Sites; Catalysis; Cold Temperature; Dipeptides/chemistry; Dipeptides/metabolism; Escherichia coli Proteins/metabolism; HSP40 Heat-Shock Proteins; HSP70 Heat-Shock Proteins/metabolism; Heat-Shock Proteins/metabolism; Isomerism; Kinetics; Luciferases/chemistry; Luciferases/metabolism; Magnetic Resonance Spectroscopy; Magnetics; Protein Folding; Protein Renaturation; Ribonuclease T1/chemistry; Ribonuclease T1/metabolism; Substrate Specificity; cis-trans-Isomerases/metabolism

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.