This NSF award funded a collaborative research project involving the laboratories of Professor Katherine Hicks at the State University of New York at Cortland and Professor Mark Snider at The College of Wooster, which are both primarily undergraduate institutions. Our research objectives were to use modern structure-function approaches to examine the bacterial degradation of N-heterocyclic aromatic compounds (NHACs), which are emerging environment pollutants. We focused our efforts on characterizing several metabolic enzymes that degrade nicotinic acid (NA), a model compound for understanding the degradation of NHACs, to understand the structural and mechanistic bases of NHAC ring hydroxylation reactions.  

The main intellectual merits of this project involved determining the crystal structures and mechanisms of several NA metabolic enzymes. For example, the Snider lab engineered and biochemically characterized active-site variants of the key flavin monooxygenase in the NA pathway, NicC, to establish the structural determinants of substrate binding. They also conducted transient state stopped-flow kinetic experiments to establish a full kinetic mechanism for the action of NicC. This kinetic model will also be useful for further investigations to understand the unique aspects of NicC's mechanism and its action with alternative substrates. In addition, the Snider laboratory identified the genes involved in NA degradation in the soil bacterium Bacillus niacini, were the first to reconstitute functional, recombinant nicotinate and 6-hydroxynicotinate dehydrogenase multi-subunit complexes, and worked with the Hicks lab to determine the structure and function of a novel flavin monooxygenase to establish several of the novel catalytic steps of this degradative pathway. Together these data allow deeper understanding of how soil bacterial enzymes catalyze unique ring hydroxylation reactions to destabilize NHACS and have the potential to inform bioremediation efforts.

The broader impacts of this project involved the training of 26 undergraduate research students in the Snider laboratory in modern biochemical techniques. These students were involved in all aspects of this work, from designing and conducting the experiments to writing and presenting formal theses and assisting in writing manuscripts for publication. All students involved in this project presented the results of their research in professional symposia at Wooster, and many also presented research posters at national meetings of the American Society for Biochemistry & Molecular Biology.   

Research students in the Hicks and Snider laboratories, along with Professors Hicks and Snider, also developed a multi-day research workshop for middle-school aged girls as part of the Buckeye Women in Science, Engineering, and Research (BWiSER) camp during the summers of 2019 and 2022 at The College of Wooster. These workshops involved approximately 60 campers who analyzed the ability of bacteria they isolated from local soil samples to degrade NHACs. In addition, this project was also adapted into a semester-long, advanced course-based research experience (CURE) for science majors at The College of Wooster. This course has been taken by 41 students to date and the resources provided by this award enables new iterations of this lab-course to be continued in the future.

Together the intellectual merits and broader impacts from this work have provided a basis for understanding the molecular details underlying ring-hydroxlyation events in NA metabolism and meaningful research experiences for the next generation of the STEM workforce.

Last Modified: 10/23/2023
Modified by: Mark J Snider