title: Identification of a critical chaperoning region on an archaeal recombinant thermosome.
abstract: Chaperone function in water-miscible organic co-solvents is useful for biocatalytic applications requiring enzyme stability in semi-aqueous media and for understanding chaperone behavior in hydrophobic environments. Previously, we have shown that a recombinant single subunit thermosome (rTHS) from Methanocaldococcus jannaschii functions in multiple co-solvents to hydrolyze ATP, prevent protein aggregation, and refold enzymes following solvent denaturation. For the present study, a truncated analog to the thermosome in which 70 N-terminal amino acids are removed is used to identify important regions within the thermosome for its chaperoning functions in organic co-solvents. Data presented herein indicate that the N-terminal region of rTHS is essential for the chaperone to restore the native state of the enzyme citrate synthase, but it is not a critical region for either binding of unfolded proteins or ATP hydrolysis. This is the first demonstration that direct refolding by a Group II chaperonin requires the N-terminal region of the protein.
authors.affiliation: Department of Chemical Engineering, University of California, 201 Gilman Hall, Berkeley, CA 94720, USA.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Bergeron
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lee
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Clark
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry*; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure*; D018833:Chaperonins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure*; D003198:Computer Simulation; D008956:Models, Chemical; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D056405:Thermosomes
chemical_list: D019843:Archaeal Proteins; D018832:Molecular Chaperones; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D018833:Chaperonins; D056405:Thermosomes