Sue Wickner received her Ph.D. from Albert Einstein College of Medicine where she studied biochemical mechanisms involved in DNA replication with Dr. Jerard Hurwitz. She received an NIH Award of Merit in 1995. A new concept in molecular biology that has evolved over the past ten years is that proteins are properly folded, unfolded and refolded with assistance from other proteins, known as molecular chaperones.
Chaperones are present in all organisms and are highly conserved.
Many are induced by environmental stresses such as heat shock. We have been studying the major 70 kDa molecular chaperone of E. coli , DnaK. DnaK is involved in many cellular processes including DNA replication, RNA synthesis, cell division, protein transport, proteolysis, protection of enzymes during heat shock, and regulation of the heat shock response. Using purified proteins, we found that the mechanism of activation is the conversion of inactive RepA dimers to active RepA monomers. The monomer, but not the dimer, binds to RepA DNA binding sites in the P1 origin of replication. DnaK, DnaJ and GrpE are not part of this protein-DNA complex.