Glutamate uptake in the Gram-positive Corynebacterium glutamicum is mediated via a binding protein-dependent transport system, which is encoded by the gluABCD gene cluster. Cloning of these genes in an expression vector and subsequent transformation of the resulting plasmid allows different strains of the Gram-negative bacterium Escherichia coli to grow on glutamate as sole carbon and nitrogen source. However, overexpression of the glutamate uptake system results in growth inhibitory effects, probably due to the particular topology of the binding protein.