ABC-type Multidrug Resistance Transporters and their Role in Survival of Bacteria
Patrick J. Bakkes, H. Bart van den Berg van Saparoea and Arnold J.M. Driessen
from: ABC Transporters in Microorganisms: Research, Innovation and Value as Targets against Drug Resistance (Edited by: Alicia Ponte-Sucre). Caister Academic Press, U.K. (2009)
Multidrug transporters are membrane proteins that actively catalyze the extrusion of structurally and functionally unrelated drugs from the cell. They are considered the major contributors to multidrug resistance (MDR) of bacterial cells. The majority of the identified MDR transporters were shown to rely on ion motive forces for their extrusion activity, while only few systems characterized thus far use ATP hydrolysis to drive efflux. There is accumulating evidence that MDR transporters also have natural physiological roles in addition to the extrusion of man-made synthetic drugs. MDR efflux pumps have been implicated in the protection against toxic compounds present in the natural environment such as bile acids, host-defense molecules and hormones. Here we summarize recent advances in the characterization of ATP-binding cassette ABC-type transporters involved in bacterial multidrug resistance with implications for their physiological functions. In addition, we will discuss possible pitfalls in the functional analysis of ABC-type MDR-like transporters in heterologous systems, and the need for functional characterization in the authentic host read more ...