1. Model of the assembled tripartite drug efflux pump.
Model of the assembled tripartite drug efflux pump. This possible model of an RND-class drug efflux pump is based on the open-state model of TolC (red) forming a minimal contact interface with the six hairpins at the apex of AcrB (green). A ring of nine MexA molecules (blue) is modeled to form a sheath around AcrB and the α-barrel of TolC (MexA is a close homologue of AcrA, the natural partner of AcrB/TolC). Variants of the model might include a lower-order oligomer of MexA (4) and more extensive interaction between AcrB and TolC. IM, inner membrane; OM, outer membrane. (Reprinted from reference 42 with permission from Elsevier and V. Koronakis.)‏
Laura J. V. Piddock Clin. Microbiol. Rev. 2006; doi: /CMR