Fig. 6
From: Structures and transport dynamics of a Campylobacter jejuni multidrug efflux pump
Proposed model of drug efflux mechanism. On the basis of our experimental data, there are at least four distinct states found in the trimeric CmeB multidrug efflux pump. These four states are labeled as low (L), intermediate-1 (I 1 ), intermediate-2 (I 2 ), and high (H) FRET states, which correspond to ~0.20, ~0.35, ~0.45, and ~0.60 FRET efficiencies. During drug export, each protomer of CmeB autonomously undergoes a sequence of conformational transitions through a particular protomer. This schematic diagram indicates that each protomer within the CmeB trimer can independently go through a sequence of conformational transitions, which lead to the extrusion of substrate (R resting, B binding, E extrusion, U unlabeled)
