This fellowship supports research and training in the area of microbial genetics. The mechanism by which a bacterium survives exposure to the toxic metal mercury is being studied using the Tn21 mercury resistance operon from a plasmid of the bacterium Shigella flexeri. The study will determine how a regulatory protein, MerR, binds to DNA and induces expression of a structural gene, merTPCAD, in response to mercury exposure. It will be determined how MerR distinguishes between mercury and other heavy metals also encountered in the environment. Mutants whose MerR recognize cadmium and zinc will be generated and characterized.
