An allosteric transport mechanism for the AcrAB-TolC multidrug efflux pump.
Wang, Z., Fan, G., Hryc, C.F., Blaza, J.N., Serysheva, I.I., Schmid, M.F., Chiu, W., Luisi, B.F., Du, D.(2017) Elife 6
- PubMed: 28355133 
- DOI: https://doi.org/10.7554/eLife.24905
- Primary Citation of Related Structures:  
5NC5, 5NG5, 5O66, 5V5S - PubMed Abstract: 
Bacterial efflux pumps confer multidrug resistance by transporting diverse antibiotics from the cell. In Gram-negative bacteria, some of these pumps form multi-protein assemblies that span the cell envelope. Here, we report the near-atomic resolution cryoEM structures of the Escherichia coli AcrAB-TolC multidrug efflux pump in resting and drug transport states, revealing a quaternary structural switch that allosterically couples and synchronizes initial ligand binding with channel opening. Within the transport-activated state, the channel remains open even though the pump cycles through three distinct conformations. Collectively, our data provide a dynamic mechanism for the assembly and operation of the AcrAB-TolC pump.
Organizational Affiliation: 
National Center for Macromolecular Imaging, Baylor College of Medicine, Houston, United States.