The retractable type IV pilus (T4P) in Gram-negative bacteria is the strongest biological motor currently known. It uses ATP as the power source to perform mechanical work through energy transformation by biological means. A dozen T4P or Pil proteins are specifically required for this motor to function. This project uses Myxococcus xanthus T4P as the experimental system to explore how Pil proteins interact with one another to make this powerful motor function. The genetic interactions among pil genes will be investigated using an innovative assay based on new discoveries that T4P regulates additional cellular functions. In addition, binary interactions among T4P proteins and their conserved domains will be investigated systematically by the yeast two-hybrid system. The successful completion of this project will provide an overview of T4P protein interactions and insights into the T4P motor and its mechanisms of energy transformation.
Broader Impact: The conceptual framework for the project crosses the boundaries of biology, physics, and engineering. Funding for this project will thus create excellent training opportunities for students in interdisciplinary research. The PI takes an active role in multiple undergraduate and graduate programs at Virginia Tech (VT). Many of these programs emphasize interdisciplinary training; these include an NSF-IGERT program, the Interdepartmental Microbiology Graduate Program (IMGP), and Scieneering. Other programs aim to broaden and create opportunities for the underrepresented in science and the disadvantaged in society; they include the Initiative for Maximizing Student Diversity, the Multicultural Academic Opportunities Program, the VT Post Baccalaureate Research and Education Program, and various summer programs for undergraduates. A few of the programs receive funding from agencies including NSF while others are initiated by the faculty and supported by various institutions at VT. In addition, the outcome of this project may prove instrumental for more efficient energy transformation and utilization which present some of the most challenging environmental issues on a global scale.