Thiamine Biosynthesis as a Model for Metabolic Pathway Integration

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

A fundamental question in biology is how metabolic pathways are integrated to result in the robust and efficient physiology that is associated with a living cell. In addressing this question, the long-term goal of this project is to define the metabolic components and understand the connections that exist between them in a bacterial cell. In the past 12 years thiamine biosynthesis in Salmonella enterica has been developed as a model system to probe metabolic integration. In the course of this work, new metabolic connections have been defined and lesions in uncharacterized open reading frames have been described phenotypically. The latter result provides the first step in functional annotation of genes that have no known or predicted function and contain no informative sequence motifs. This project will probe the function of YggX, an open reading frame that was identified in the PI's laboratory as part of past metabolic work. Based on previous work (both in vivo and in vitro) a working model has been developed that suggests YggX has a role in iron trafficking in Salmonella. The function of YggX will be addressed at two general levels. First, the in vivo function of YggX will be explored in the context of other cellular components that are involved in maintaining iron homeostasis in the cell. Second, a high-resolution structure will be determined by NMR, and in vitro biochemical characterization of the wild type and mutant forms of YggX will be preformed. This work will contribute to the overall understanding of metabolism by defining function of the YggX protein in the context of cellular metabolism. An understanding of metabolism in this context is critical for efforts to capture and exploit biological processes for the good of mankind. In a broad context, this work will provide rigorous multi-disciplinary training to young scientists. High school, undergraduate and graduate students will participate in the research. Components of this research plan will be incorporated into undergraduate and graduate laboratory courses being designed by the PI. The PI will present this work in many forums that target general audiences and continue to actively participate in the recruitment and mentoring of women and underrepresented groups in scientific research.