SMRSSNMR · Solid state NMR study of small multidrug resistance proteins

Small multidrug resistance proteins (SMR) were proven to be one of the responsible factors for drug resistance of bacteria, which represents an actual and serious problem in the therapy of several infectious diseases. Despite of the recent extensive biochemical investigations of SMR proteins the mechanism of substrate recognition and translocation is not yet clearly understood. The aim of the proposed project is the investigation of substrate-protein interaction between a selected SMR protein (e.g. EmrE or TBsmr) and various substrates using solid state NMR and complementary biochemical and biophysical methods. This means investigation of the changes in protein structure and dynamics on interaction with the substrate molecule and assessment of the substrate binding sites. The results are expected to gain an insight into the structure and transport mechanism of SMR proteins. Three different technical and methodological aspects are essential for the progress of this project. 1. Expression and isotop labeling of proteins with protocols already available in the host laboratory which can be optimised for the selected protein if necessary. 2. Reconstitution of proteins into lipid vesicles, in order to obtain the protein as close to its naturally active form as possible and in sufficiently high concentration. 3. Study of substrate-protein interaction with different MAS NMR methods and complementary techniques (if necessary) such as fluorescence spectroscopy. On the last few month of the fellowship first experiments will start on a selected zinc transporter protein (expression and reconstitution), which will be continued after the return of the applicant to the home university in Szeged, Hungary. The project will provide the applicant with training in expression and handling of membrane proteins and in solid state NMR. The aquired skills and knowledge will help the applicant to resume her research career after a break and in obtaining a permanent university position.