title: Heat-inactivated proteins managed by DnaKJ-GrpE-ClpB chaperones are released as a chaperonin-recognizable non-native form.
abstract: Chaperones of Thermus thermophilus cooperate in reactivation of heat-inactivated proteins. The protein, inactivated at a high temperature in a TDnaKJ-GrpE set, recovered its activity during subsequent incubation with TClpB at moderate temperature (Motohashi, K., Watanabe, Y., Yohda, M., and Yoshida, M. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 7184-7189). Here, we report that the addition of chaperonin (Tcpn) at moderate temperature improves the yield of the TDnaKJ-GrpE-ClpB-dependent reactivation. The trap-Tcpn, which binds substrate protein but does not release it, inhibits reactivation severely. Maximum recovery is gained at sub-stoichiometric amounts of each component of TDnaKJ, TGrpE, and TClpB relative to the substrate monomer. These observations indicate that, driven by ATP hydrolysis, TDnaKJ-GrpE-ClpB chaperones catalytically cooperate and release heat-inactivated protein as a non-native, chaperonin-recognizable folding intermediate.
authors.affiliation: Chemical Resources Laboratory, R-1, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama 226-8503, Japan.
authors.forename: Y H
authors.initials: YH
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Motohashi
authors.forename: H
authors.initials: H
authors.lastname: Taguchi
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D018833:Chaperonins / Q000502:physiology*; D049071:Endopeptidase Clp; D029968:Escherichia coli Proteins; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000502:physiology*; D006358:Hot Temperature; D018832:Molecular Chaperones / Q000502:physiology; D010957:Plasmids; D011485:Protein Binding; D013997:Time Factors; D000520:alpha-Glucosidases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C068113:GrpE protein, Bacteria; C489400:GrpE protein, E coli; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D005954:Glucosephosphate Dehydrogenase; D000520:alpha-Glucosidases; D049071:Endopeptidase Clp; D018833:Chaperonins; C063842:dnaK protein, E coli; C069775:ClpB protein, E coli