Hydrophobic interactions between molecular chaperones and their nonnative substrates have been believed to be mainly responsible for both substrate recognition and stabilization against aggregation. However, the hydrophobic contact area between DnaK and its substrate proteins is very limited and other factors of DnaK for the substrate stabilization could not be excluded. Here, we covalently fused DnaK to the N-termini of aggregation-prone proteins in vivo. In the context of a fusion protein, DnaK has the ability to efficiently solubilize its linked proteins. The point mutation of the residue of DnaK critical for the substrate recognition and the deletion of the C-terminal substrate-binding domain did not have significant effect on the solubilizing ability of DnaK. The results imply that other factors of DnaK, distinct from the hydrophobic shielding of folding intermediates, also contributes to stabilization of its noncovalently bound substrates against aggregation. Elucidation of the nature of these factors would further enhance our understanding of the substrate stabilization of DnaK for expedited protein folding.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2008 Aug 15|
Bibliographical noteFunding Information:
This work was supported in part by the Microbial Genomics R&D Grants from the Ministry of Science and Technology of Korean Government (Grant No. MG05-0306-3-0) and the Korea Research Foundation Grant by the Korean Government (Grant No. KRF-2004-005-C00148).
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology