title: Heat shock protein 70 kDa chaperone/DnaJ cochaperone complex employs an unusual dynamic interface.
abstract: The heat shock protein 70 kDa (Hsp70)/DnaJ/nucleotide exchange factor system assists in intracellular protein (re)folding. Using solution NMR, we obtained a three-dimensional structure for a 75-kDa Hsp70-DnaJ complex in the ADP state, loaded with substrate peptide. We establish that the J domain (residues 1-70) binds with its positively charged helix II to a negatively charged loop in the Hsp70 nucleotide-binding domain. The complex shows an unusual "tethered" binding mode which is stoichiometric and saturable, but which has a dynamic interface. The complex represents part of a triple complex of Hsp70 and DnaJ both bound to substrate protein. Mutagenesis data indicate that the interface is also of relevance for the interaction of Hsp70 and DnaJ in the ATP state. The solution complex is completely different from a crystal structure of a disulfide-linked complex of homologous proteins [Jiang, et al. (2007) Mol Cell 28:422-433].
authors: Biological Chemistry, and Lifesciences Institute, University of Michigan, Ann Arbor, MI 48109, USA.
authors: Atta
authors: A
authors: Ahmad
authors: Akash
authors: A
authors: Bhattacharya
authors: Ramsay A
authors: RA
authors: McDonald
authors: Melissa
authors: M
authors: Cordes
authors: Benjamin
authors: B
authors: Ellington
authors: Eric B
authors: EB
authors: Bertelsen
authors: Erik R P
authors: ER
authors: Zuiderweg
mesh_terms: D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism*; D016296:Mutagenesis; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; D046912:Multiprotein Complexes