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M Domains Couple the ClpB Threading Motor with the DnaK Chaperone Activity
- Source :
- Molecular Cell. 25(2):247-260
- Publication Year :
- 2007
- Publisher :
- Elsevier BV, 2007.
-
Abstract
- 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.
- Subjects :
- 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
Subjects
Details
- ISSN :
- 10972765
- Volume :
- 25
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- Molecular Cell
- Accession number :
- edsair.doi.dedup.....418536264f41c800d15d24278a263156
- Full Text :
- https://doi.org/10.1016/j.molcel.2006.11.008