DNA polymerase III, the core of the DNA polymerase III holoenzyme, has been purified Z&000-fold to 97% homogeneity from Escherichiu coli HMS-83. The enzyme contains three subunits: (Y, E, and 0 of 140,000, 25,000, and 10,000 daltons, respectively. The cy subunit has been previously shown to be a component of both DNA polymerase III and the more complex DNA polymerase III holoenzyme (Livingston,...