The reconstitution of binding protein-dependent active transport of glutamine in isolated membrane vesicles from Escherichia coli

Abstract

The reconstitution of binding protein-dependent glutamine transport in isolated membrane vesicles from Escherichia coli is described. The reconstituted glutamine transport is shown to be energy-dependent and does not involve the metabolism of glutamine or the trapping of liganded binding protein with the vesicles. The preparation of vesicles capable of transporting glutamine in a binding protein-dependent manner required the incorporation of NAD into vesicles and the use of a binding protein point mutant as the source of the vesicles.