title: Functional characterization of the DnaK chaperone system from the archaeon Methanothermobacter thermautotrophicus DeltaH.
abstract: We characterized the biochemical and functional properties of the DnaK system from the archaeon Methanothermobacter thermautotrophicus DeltaH. In contrast to the eubacterial chaperone components the archaeal Hsp70 system shows thermal transitions only slightly above the optimal environmental temperature (65 degrees C). Nevertheless, it prevents aggregation of luciferase in the physiological temperature range of the organism, but is also fully functional at 30 degrees C in luciferase refolding. Additionally, GrpE(M.th.) and DnaJ(M.th.) substitute their eubacterial counterparts whereas DnaK(M.th.) is only functional with its native cochaperones which could be attributed to a functional specialization of the eubacterial chaperones during evolution.
authors.affiliation: Max-Planck-Institute for Medical Research, Department of Biomolecular Mechanisms, Heidelberg, Germany.
authors.forename: Simone L
authors.initials: SL
authors.lastname: Popp
authors.forename: Jochen
authors.initials: J
authors.lastname: Reinstein
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D017930:Genes, Reporter / Q000235:genetics; D019791:Guanidine / Q000494:pharmacology; D017013:Methanobacteriaceae / Q000201:enzymology* / Q000235:genetics; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D017510:Protein Folding
chemical_list: D019843:Archaeal Proteins; D018832:Molecular Chaperones; D000251:Adenosine Triphosphatases; D019791:Guanidine