Studies with DNA-cellulose Chromatography. I. DNA-binding Proteins from Escherichia coli

Abstract

A fascinating variety of proteins must interact with DNA within the cell in order to make possible such basic genetic processes as DNA replication and repair, DNA recombination, selective gene expression, and mRNA transcription. Before gene function can be precisely defined at the molecular level, many such DNA-associated proteins will have to be individually isolated and characterized. We have developed a general method which should facilitate such analyses. This method, which we call 'DNA-cellulose chromatography', relies upon the fact that many of the proteins which function on DNA inside the cell bind tightly to DNA at physiological ionic strengths in vitro. At higher salt concentrations these proteins are reversibly released from the DNA, apparently in an undamaged state. Previously characterized proteins with such binding properties include the E. coli RNA polymerase (J. R. Richardson, 1966b; Pettijohn and Kamiya, 1967) and the lactose and phage λ repressors (Gilbert and Muller-Hill, 1967;...