Ben Luisi's group and their collaborators have published a paper in Nature "Structure of the AcrAB–TolC multidrug efflux pump". Many bacterial species can tolerate antibiotics and other toxic compounds partly because of energy-dependent transporters. In Gram-negative bacteria, many of these transporters form multicomponent ‘pumps’. A model system for such a pump is the acridine resistance complex of Escherichia coli. Homologous systems are found in many other Gram-negative species, including animal and plant pathogens. Crystal structures are available for the individual components of the pump and have provided insights into substrate recognition, energy coupling and the transduction of conformational changes associated with the transport process. However, how the subunits are organized in the pump, their stoichiometry and the details of their interactions were not known. The structure of a complete multidrug efflux pump in complex with a modulatory protein partner from E. coli has been solved in this work. The model defines the quaternary organization of the pump, identifies key domain interactions, and suggests a cooperative process for channel assembly and opening.