The research will investigate coenzyme B12-dependent 1,2-propanediol degradation by Salmonella enterica. Because B12-dependent processes are critically important to the environment and biotechnology industry, these studies may provide information helpful for protecting the environment and reducing the cost of industrial chemicals. The aims of the project focus on vitamin B12 recycling and on an unusual polyhedral body needed for the efficient functioning of vitamin B12. These polyhedral bodies are one of the largest macromolecular complexes known in biology. They consist of metabolic enzyme encased within a multi-protein shell. Prior studies have indicated that they function as microcompartments that sequester toxic metabolic intermediates. Investigations will center on understanding how these compartments affect activity of B12-dependent enzymes, and will test the hypothesis that they act as microcompartments. In addition, the assembly and three-dimensional structure of the microcompartments will be investigated.
Broader impacts: This research will contribute to the scientific education of two graduate students and one postdoctoral fellow. Students will receive broad training in the use of genetic, biochemical, and immunological methods for the study of bacterial metabolism. The project will provide research opportunities to African-American undergraduate students through the Iowa State University Carver Foundation. The research may provide information helpful to the industrial production of 1,3-propanediol (a base ingredient of a commercial polymer) since B12-dependent diol dehydratase is a key enzyme for this process. This field is expected to become increasingly important as the need to engineer microbes for the production of chemicals from renewable resources grows in the coming years.
