E. coli Mutants Lacking the dnaK Heat Shock Gene: Identification of Cellular Defects and Analysis of Suppressor Mutations
We investigated the role of the DnaK (HSP70) ehaperone In metabolism of Escherichia coli by analyzing cellular defects caused by deletion of the dnaK gene (ΔdnaK52). ΔdnaK52 mutants are cold sensitive as well as temperature sensitive and thus possess a very narrow temperature range for growth. At intermediate (30°C) temperature, ΔdnaK52mutants display severe defects in major cellular processes such as cell division, chromosome segregation, replication of low copy number plasmids and regulation of heat shock gene expression that lead to poor growth and genetic instability of the cells. These results indicate important functions of DnaK in cellular metabolism of E. coli at a wide range of growth temperatures.
KeywordsHeat Shock Heat Shock Protein Wild Type Cell Heat Shock Response Heat Shock Gene
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