Membrane transport proteins – channels and energy-coupled pumps – are the molecular gatekeepers of the cell.  For microbes afloat in a hostile environment, these proteins import vital nutrients and export dangerous toxins.  Bacteria have contended with vast and unusual chemical threats throughout evolutionary time, and retain a catalogue of idiosyncratic export proteins to deal with hostile elements. Delving deeply into bacterial export systems reveals novel physiologies and structural surprises.

My lab focuses on understanding these weird membrane proteins. Right now, our projects revolve around exporters of two different toxic ions: fluoride and guanidinium. We have four big questions: what do they look like, how do they work, how did they evolve, and what is their biological role? We use a breadth of biochemical and biophysical techniques, including electrophysiology, membrane protein biochemistry, x-ray crystallography, and macromolecular NMR.

Crystal structure of Fluc channel with F- ions bound