Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2018-2019)

Phosphorylated-Carbohydrate Transport Across the Bacterial Cell Envelope
Bacteria depend on the acquisition of a diverse set of nutrients from their hosts to engage in successful growth, colonization or pathogenesis. Commensal and/or pathogenic bacteria compete with host cells for substrates ranging from metals to vitamins. As this competition can influence the outcome of infection, pathogens have developed a variety of nutrient uptake mechanisms to increase their competitiveness and hence their ability to colonize and productively infect their hosts. The long-term objective of my research programs is to elucidate the molecular basis of bacterial nutrient uptake by isolating membrane proteins and performing atomic resolution structural and functional characterization using a unique combination of X-ray crystallography and other biophysical tools such as microscale thermophoresis and biolayer interferometry, surface plasmon resonance and isothermal titration calorimetry.
My NSERC research focuses on nutrient uptake mechanisms via the binding-protein dependent transporters (BPDTs), which target diverse ligands such as metal ions, amino acids and sugars and are recognized as virulence determinants in many bacterial infections (Hollenstein et al., 2007). My short-term objectives outlined in this proposal are to decipher the mechanism of AfuABC a binding protein dependent transporter that we determined is responsible for active uptake of phosphorylated carbohydrates. Our structural insights will provide the molecular basis of nutrient scavenging from the host and how these bacteria compete for nutrients in complex environments.
Aim 1. Characterize the identify AfuABC homologs and paralogs for substrate specificity and transport.
Aim 2. Dissect the mechanism of transport of phospho-sugars by AfuABC using crystal structures, growth assays and biomolecular interactions to probe the interaction between the AfuA and AfuBC components of the uptake system.
These aims will lead to a critical understanding of phospho-sugar nutrient acquisition by bacterial pathogens and how this process provides a competitive advantage in their environment. In addition, this research program will provide tools to investigate membrane proteins and their interactions, providing an ideal and unique training environment for my 5 graduate students and 2 postdoctoral fellows, 3 of whom will be involved in conducting the microbiology, biochemistry and biophysical methods outline in aims 1 and 2. In keeping with my successful training of highly qualified personnel to date, my trainees will have the opportunity to contribute to high-impact publications and will gain broad expertise in membrane protein structural biology, microbiology, and biochemistry, preparing them for careers in basic scientific research and biotechnology.