Bioenergetics of dihydrostreptomycin transport by Escherichia coli.

Previous demonstrations of the irreversibility of dihydrostreptomycin transport across the cytoplasmic membrane of Escherichia coli were not due to decreases in the magnitude of the cytoplasmic membrane potential (delta psi). Irreversibility was probably not due to ATP hydrolysis being coupled to transport, because the rate of energy-dependent dihydrostreptomycin uptake was unaffected by 10-fold reduction in the cellular ATP level.