THE ESCHERICHIA-COLI DNAK CHAPERONE MACHINE AND BACTERIOPHAGE-MU LATETRANSCRIPTION

Bacteriophage Mu does not grow on temperature-sensitive E. coli dnaK m utants at elevated temperatures because of a defect in late transcript ion. As the Mu-encoded C protein is required for activation of transcr iption from the phage late promoters, we attempted to determine if Dna K and its accessory proteins DnaJ and GrpE are required for synthesis of C protein or at a later step. We found that the chaperones act in M u late transcription beyond C-protein synthesis, and that C-protein st ability is decreased in the mutant hosts. This suggests that the DnaK chaperone machine may be required for the proper folding and/or multim erization of C protein.