Send to

Choose Destination
J Biol Chem. 2006 May 5;281(18):12436-44. Epub 2006 Mar 13.

The role of the DIF motif of the DnaJ (Hsp40) co-chaperone in the regulation of the DnaK (Hsp70) chaperone cycle.

Author information

Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, 1, rue Michel-Servet, CH-1211, Geneva, Switzerland.


To perform effectively as a molecular chaperone, DnaK (Hsp70) necessitates the assistance of its DnaJ (Hsp40) co-chaperone partner, which efficiently stimulates its intrinsically weak ATPase activity and facilitates its interaction with polypeptide substrates. In this study, we address the function of the conserved glycine- and phenylalanine-rich (G/F-rich) region of the Escherichia coli DnaJ in the DnaK chaperone cycle. We show that the G/F-rich region is critical for DnaJ co-chaperone functions in vivo and that despite a significant degree of sequence conservation among the G/F-rich regions of Hsp40 homologs from bacteria, yeast, or humans, functional complementation in the context of the E. coli DnaJ is limited. Furthermore, we found that the deletion of the whole G/F-rich region is mirrored by mutations in the conserved Asp-Ile/Val-Phe (DIF) motif contained in this region. Further genetic and biochemical analyses revealed that this amino acid triplet plays a critical role in regulation of the DnaK chaperone cycle, possibly by modulating a crucial step subsequent to DnaK-mediated ATP hydrolysis.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center