Regulation of the -methylgalactoside Transport System and the Galatose-binding Protein by the Cell Cycle of Escherichia Coli

The synthesis of the periplasmic galactose-binding protein of E. coli is regulated by events occurring during its cell cycle, and proceeds in synchronized cells for only a short period after cell division is completed. Transport activity mediated by the beta-methylgalactoside transport system follows closely the synthesis pattern of the binding protein.A mutant, E. coli BUG-6, exhibits temperature-sensitive cell division [Reeve et al. (1970) J. Bacteriol. 104, 1052-1064], synthesizing galactose-binding protein at the permissive but not at the nonpermissive temperature. Galactose-binding protein synthesized at the permissive temperature is not degraded after the culture is shifted to the nonpermissive temperature. Polyacrylamide gel electrophoresis of the periplasmic proteins of BUG-6 grown at the permissive and nonpermissive temperatures suggests that several, but not all, periplasmic proteins are subject to the same regulatory control by the cell cycle as the galactose-binding protein.