M Domains Couple the ClpB Threading Motor with the DnaK Chaperone Activity
| Autor: | Jimena Weibezahn, Regina Zahn, Tobias Haslberger, Bernd Bukau, Francis T.F. Tsai, Axel Mogk, Sukyeong Lee |
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| Rok vydání: | 2007 |
| Předmět: |
Models
Molecular Endopeptidase Clp Molecular Sequence Data Protein Structure Secondary Adenosine Triphosphate Protein structure Bacterial Proteins Heat shock protein Escherichia coli HSP70 Heat-Shock Proteins Amino Acid Sequence Protein Structure Quaternary Molecular Biology Heat-Shock Proteins Adenosine Triphosphatases Sequence Homology Amino Acid biology Escherichia coli Proteins Molecular Motor Proteins Thermus thermophilus Cell Biology Translocon biology.organism_classification Protein Structure Tertiary Biochemistry Chaperone (protein) Mutagenesis Site-Directed biology.protein Biophysics Threading (protein sequence) CLPB Molecular Chaperones |
| Zdroj: | Molecular Cell. 25(2):247-260 |
| ISSN: | 1097-2765 |
| DOI: | 10.1016/j.molcel.2006.11.008 |
| Popis: | The AAA(+) chaperone ClpB mediates the reactivation of aggregated proteins in cooperation with the DnaK chaperone system. ClpB consists of two AAA domains that drive the ATP-dependent threading of substrates through a central translocation channel. Its unique middle (M) domain forms a coiled-coil structure that laterally protrudes from the ClpB ring and is essential for aggregate solubilization. Here, we demonstrate that the conserved helix 3 of the M domain is specifically required for the DnaK-dependent shuffling of aggregated proteins, but not of soluble denatured substrates, to the pore entrance of the ClpB translocation channel. Helix 3 exhibits nucleotide-driven conformational changes possibly involving a transition between folded and unfolded states. This molecular switch controls the ClpB ATPase cycle by contacting the first ATPase domain and establishes the M domain as a regulatory device that acts in the disaggregation process by coupling the threading motor of ClpB with the DnaK chaperone activity. |
| Databáze: | OpenAIRE |
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