Grant: Discovery Grants Program - Individual

Living cells are delimited by membranes that restrict the movement of molecules between the cell's cytoplasm and the external environment. Cells must grow, divide, and communicate with each other, and to accomplish these things, molecules must be transported across the membrane. Membrane transporters are protein machines that are embedded in the membrane and use energy to move specific molecules into or out of the cell. The proposed research is focussed on understanding the function of a group of transport systems that bacteria use to acquire nutrients from their environment. The nutrient acquisition systems in bacteria, also known as ""ATP Binding Cassette (ABC) Import Systems"", function as a kind of ""vacuum cleaner"", picking up nutrients from the environment and moving them into the cell. The systems have a peripheral protein on the outside of the cell that binds to a nutrient molecule and then interacts with membrane-embedded components. The interaction between the nutrient-bound peripheral protein and the membrane-embedded components causes changes in the structures of both partners, leading to hydrolysis of ATP (the cell's energy ""currency"") along with movement of the nutrient through the membrane-embedded components and into the cytoplasm.The proposed studies will define the individual molecular events that occur during the transport process, and help us to understand how energy is coupled to acquisition of nutrients. The research may offer routes to new antibiotics, and the knowledge gained can be applied to related ABC transport systems that have important functions in all forms of life.