Inorganic mercury is toxic because it reacts with sulfur atoms in proteins interfering with their physiological function. Bacteria avoid such toxicity by transporting mercury found in the periplasm to the cytoplasm where toxic Hg(II) ions are reduced to a less toxic and volatile Hg(0) form. Three proteins in the bacterial mer operon are directly involved in the transport mechanism: a periplasmic mercury binding protein, a transporter and a mercury reductase. The goal of this research project is to understand at an atomic level how periplasmic mercury is transported across the membrane to the cytoplasm to reach the mercury reductase active site without first reacting with other proteins. Our experimental approach combines structural, biochemical and physiological information. Detailed knowledge on bacterial mercury uptake will facilitate the implementation of improved bioremediation schemes to decontaminate waters and soils from pollution caused by mercury.
The broader impact of the project is to expand our undergraduate and graduate curriculum to integrate our research efforts in Structural Biochemistry to the teaching of Biochemistry and to make a conscious and concerted effort to increase the presence of underrepresented minorities in the Biochemistry research community.
