We are requesting funds to support an undergraduate student researcher during the summer months of 2022. In particular, Charlene Manipon is an undergraduate in the Biochemistry program at New York University and she has recently joined the Stokes lab to pursue a project suitable for an honors thesis associated with her Bachelor's degree. She is currently learning about the background of the project and about the biophysical tools that we use to analyze structure and function of YiiP, which is the main target of the parent grant. Although she is only able to work limited hours during the school year, this supplement will allow her to work full time on this project over the summer. In addition, she will participate in programmatic activities associated with the Summer Program for Undergraduate Researchers, which is run annually by the Vilcek Graduate Institute of Biomolecular Sciences, including career-building seminars, social events and attendance of the Leadership Alliance National Symposium where she will present her work. As a member of the Stokes lab, she will also attend group meetings and Work-in-Progress seminars associated with our graduate program in Biochemistry and Molecular Biophysics as well as with the Ion Channels and Transporters in Immunology. The project will focus on allosteric control of zinc transport by the cation diffusion facilitator YiiP, which is consistent with the aims of the parent grant. In particular, she will use analytical methods such as microscale thermophoresis, atomic absorption spectroscopy, solid supported membrane electrophysiology and fluorimetry to assess zinc binding and transport activity of a variety of mutants. These studies will be designed to understand roles of the three distinct zinc binding sites either in stabilizing the structure of the homodimer or in eliciting allosteric changes associated with transport.