title: Unraveling the mechanism of protein disaggregation through a ClpB-DnaK interaction.
abstract: HSP-100 protein machines, such as ClpB, play an essential role in reactivating protein aggregates that can otherwise be lethal to cells. Although the players involved are known, including the DnaK/DnaJ/GrpE chaperone system in bacteria, details of the molecular interactions are not well understood. Using methyl-transverse relaxation-optimized nuclear magnetic resonance spectroscopy, we present an atomic-resolution model for the ClpB-DnaK complex, which we verified by mutagenesis and functional assays. ClpB and GrpE compete for binding to the DnaK nucleotide binding domain, with GrpE binding inhibiting disaggregation. DnaK, in turn, plays a dual role in both disaggregation and subsequent refolding of polypeptide chains as they emerge from the aggregate. On the basis of a combined structural-biochemical analysis, we propose a model for the mechanism of protein aggregate reactivation by ClpB.
authors: Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada. rina.rosenzweig@utoronto.ca
authors: Rina
authors: R
authors: Rosenzweig
authors: Shoeib
authors: S
authors: Moradi
authors: Arash
authors: A
authors: Zarrine-Afsar
authors: John R
authors: JR
authors: Glover
authors: Lewis E
authors: LE
authors: Kay
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics; D006868:Hydrolysis; D008956:Models, Chemical; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D054730:Protein Interaction Domains and Motifs; D060066:Protein Interaction Maps; D055503:Protein Multimerization; D058849:Protein Refolding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D016963:Thermus thermophilus
chemical_list: D001426:Bacterial Proteins; C068113:GrpE protein, Bacteria; D006360:Heat-Shock Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases