Mutation clp A::kan of the Gene for an HsplOO Family Chaperone Impairs the DnaK-Dependent Refolding of Proteins in Escherichia coli

摘要

The rate and level of DnaK-dependent refolding of heat-inactivated Vibrio fischeri luciferase in the dp A mutant(clpAv.kan)were considerably lower then in wild-type cells.The decline in refolding level progressed with increasing heat inactivation time.A mutation of clpP had no influence on the kinetics and level of luciferase refolding.Approximately equal amounts of the DnaKJE chaperone were synthesized upon heat shock induction in E.coli clpA~+ and E.coli clpA::kan cells.It was assumed that,like homologous chaperone ClpB,ClpA is involved in disaggregation of denatured proteins,increasing the refolding efficiency.This in vivo phenomenon occurred only upon a prolonged incubation of cells at a higher temperature,which led to the formation of large protein aggregates that were poorly refoldable by the DnaKJE system.