title: DnaK ATPase activity revisited.
abstract: It has recently been reported that the ATPase activity of DnaK, a 70 kDa heat shock protein from E. coli, is autostimulated by increasing protein concentration [(1993) FEBS Lett. 322, 277-279], suggesting that the DnaK dimer may be the enzymatically active species. In this paper we investigated the ATPase activity of different DnaK preparations; we found that the turnover number was very dependent on protein purification. With HPLC-purified DnaK we found a turnover number 20- to 50-fold lower than typical values previously published and no evidence of autostimulation, indicating that the monomer is the active species.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
authors.forename: D R
authors.initials: DR
authors.lastname: Palleros
authors.forename: K L
authors.initials: KL
authors.lastname: Reid
authors.forename: L
authors.initials: L
authors.lastname: Shi
authors.forename: A L
authors.initials: AL
authors.lastname: Fink
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D000251:Adenosine Triphosphatases; C063842:dnaK protein, E coli