We will seek seek in this BmrA-NMX project to reveal structure features of the different conformational states of BmrA, an ABC efflux pump, using N for NMR, M for Mass spectrometry, and X for X-ray crystallography methods. BmrA is, other members of ABC transporters family, able to transport a wide variety of drugs. Multidrug resistance due to efflux pumps has strong implication in medicine because it is found from humans to bacteria. We will use state-of-the art biochemical studies to identify and characterize different conformational states, using wild-type and mutant forms, and drug-bound forms. Drug binding and transport abilities of the corresponding states of BmrA will be quantified and transposed to crystallogenesis, mass spectrometry and solid-state NMR experiments. These approaches will be used to gain insight into the structural features of the membrane pump. They will deliver complementary structural parameters, such as the overall 3D structure, detailed information on conformational changes as a function of state, and stability and accessibility of secondary structure elements. Sample preparations of the different forms will be established using feed back from the biochemical studies, and crystalline, as well as membrane-bound, drug-bound and mutant forms will be made for the different studies. The unique combination of structural techniques is expected to obtain a comprehensive picture of the processes involved in drug export. Such knowledge will be an important steppingstone towards deciphering the molecular mechanism underlying drug export.