Certain soil bacteria will utilize aliphatic sulfonates in the environment to obtain sulfate if standard sources are not available. The enzyme system involved in this process is comprised of a flavin-reductase (SsuE) involved in providing reduced flavin to the monooxygenase enzyme (SsuD) that is directly involved in the desulfonation reaction. This fascinating enzyme system belongs to an increasing number of two-component enzyme systems that utilize flavin as a substrate rather than a bound prosthetic group. These systems include proteins involved in the degradation of herbicides, the synthesis of antibiotics, desulfurization of pollutants, and bioluminescence. The broad objective of these studies is to elucidate the mechanism of the alkanesulfonate monooxygenase system. The primary goal of this research focuses on two highly interesting features of this enzyme system: 1) the mechanism of C-S bond cleavage by SsuD 2) the reduced flavin transfer mechanism between SsuE and SsuD. Relating the results obtained from these studies of the alkanesulfonate monooxygenase proteins to other flavin transfer systems will enhance our knowledge of a family of enzymes with highly diverse functions.
The educational goal of this project is to enhance the Auburn Science in Motion program by introducing biochemical experiments to the existing curriculum. The Science in Motion program was established by the Alabama State Legislature to bring technologically advanced laboratory experiments to local high school classrooms. The educational component will be implemented through three distinct activities: 1. experimental development 2. graduate student outreach 3. direct training to high school educators. The impact of this project will affect students from all levels and introduce those students from underrepresented groups and economically disadvantaged school districts to innovative experiments, which can increase student interest in science and influence their future educational decisions.
Intellectual Merit For many bacterial organisms, inorganic sulfate is an important metabolite in the biological synthesis of sulfur-containing macromolecules. Inorganic sulfur is often poorly represented in the environment, therefore bacteria must have alternative sources for obtaining this element. The alkanesulfonate monooxygenase system plays a critical role in maintaining appropriate sulfur concentrations in bacterial cells for diverse metabolic events. The enzyme system is able to utilize diverse alkanesulfonate substrates in the acquisition of sulfite for incorporation into biologically relevant macromolecules. The broad objective of this project was to fully establish the mechanism of the alkanesulfonate monooxygenase system. The primary goal of these studies were focused on two highly interesting features of this system 1) oxygenolytic cleavage of the C-S bond by SsuD 2) flavin transfer between SsuE and SsuD. The results from these studies resulted in defining the mechanistic and structural properties of the alkanesulfonate monooxygenase system. Relating the results obtained from these studies of the alkanesulfonate monooxygenase proteins to other flavin transfer systems has enhanced our knowledge of a family of enzymes with highly diverse functions. In addition, the insight obtained from these findings has provided exciting new research areas to investigate. Broader Impact A principle educational component of the proposal was focused on the inclusion of biochemistry experiments to the Science in Motion Program at Auburn University. This program is designed to bring technologically advanced experiments to the high school classroom. Each site is equipped with a specialist involved in teacher training, experimental development, delivery of laboratory equipment, and classroom instruction. Many of these schools are located in districts where the cost of the equipment alone would be prohibitive. The Science in Motion program ensures that all students are afforded similar learning opportunities by providing equal access to modern technology, especially for those students in rural areas located in economically disadvantaged school systems. In addition, the program offers students from underrepresented groups the opportunity to learn innovative science techniques that will lead to an increase in student interest and participation in science courses and careers. The goal of the educational component was to establish biochemical experiments for Science in Motion that could be used in the local high school chemistry and biology classes. Each experiment was designed to the specifications of the Alabama Course of Study. These experiments were presented through demonstrations at the summer workshop for high school educators, and the materials needed to conduct the experiments were supplied by the state. Initially Auburn was only assigned a chemistry specialist, but a biology focus has also been added. Therefore, the biochemistry experiments can now be implemented in both the chemistry and biology section. This program assisted in developing an important link between high school and college educators.
