A novel ATP-driven glucose transport system in Escherichia coli

In Escherichia coli wild-type cells and in ATPase-deficient cells (unc mutants), glucose was found to be transported mainly by an ATP-driven system. The evidence is based on experiments involving interference at different sites of energy metabolism with the use of uncouplers, arsenate, and starved cells. Furthermore, addition of succinate to starved cells increased glucose uptake only in the wild-type cells, where ATP could be regenerated. Glucose transport was also ATP-dependent in cells deficient in methyl-beta-galactoside transport (a system that carries glucose specificity). It was found to be shock-sensitive in all strains tested. The NOVEL ATP-driven glucose transport is a high-affinity (Km 3-10 microM) and high-capacity (V 240-330 Mmol . min-1 . mg cell protein-1) uptake system.