Activity of the Hsp70 chaperone complex--DnaK, DnaJ, and GrpE--in initiating phage lambda DNA replication by sequestering and releasing lambda P protein

Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):12108-11. doi: 10.1073/pnas.89.24.12108.


Initiation of DNA replication by phage lambda requires the ordered assembly and disassembly of a specialized nucleoprotein structure at the origin of replication. In the disassembly pathway, a set of Escherichia coli heat shock proteins termed the Hsp70 complex--DnaK, DnaJ, and GrpE--act with ATP to release lambda P protein from the nucleo-protein complex, freeing the DnaB helicase for its DNA-unwinding reaction. To investigate the mechanism of the release reaction, we have examined the interaction between P and the three heat shock proteins by glycerol gradient sedimentation and gel electrophoresis. We have discovered an ATP-dependent ternary interaction between P, DnaK, and DnaJ; this P.DnaK.DnaJ complex is dissociated by GrpE. We have concluded that the function of the Hsp70 complex in sequestering and releasing P protein provides for the critical step in the disassembly pathway. Based on our data and other work on protein folding, the formation of the P.DnaK.DnaJ complex might involve a conformational shift to a folding intermediate of P.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Bacteriophage lambda / genetics*
  • Chaperonins
  • DNA Helicases*
  • DNA Replication*
  • DNA, Viral / metabolism
  • DNA-Binding Proteins / metabolism
  • DnaB Helicases
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins*
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins*
  • Heat-Shock Proteins / metabolism*
  • Macromolecular Substances
  • Protein Binding
  • Proteins / metabolism*
  • Viral Proteins / metabolism*
  • Virus Replication*


  • Bacterial Proteins
  • DNA replication complex protein, Bacteriophage lambda
  • DNA, Viral
  • DNA-Binding Proteins
  • DnaJ protein, E coli
  • Escherichia coli Proteins
  • GrpE protein, Bacteria
  • GrpE protein, E coli
  • HSP40 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Macromolecular Substances
  • Proteins
  • Viral Proteins
  • Chaperonins
  • dnaK protein, E coli
  • DNA Helicases
  • DnaB Helicases