The structures of MsbA: Insight into ABC transporter-mediated multidrug efflux.

ATP-binding cassette (ABC) transporters are integral membrane proteins that couple ATP hydrolysis to the transport of various molecules across cellular membranes. Found in both prokaryotes and eukaryotes, a sub-group of these transporters are involved in the efflux of hydrophobic drugs and lipids, causing anti-microbial and chemotherapeutic multidrug resistance. In this review, we examine recent structural and functional analysis of the ABC transporter MsbA and implications on the mechanism of multidrug efflux.