Shelby Parrott Graduate Student, Department of Chemistry University of Georgia Monday, April 4, 2022 - 11:30am Chemistry Building, Room 400 Inorganic Seminar Heme is an essential cofactor required for numerous biological reactions in the vast majority of organisms, and its biosynthesis is a complex process. Three heme biosynthetic pathways have been identified, with the most recent being the coproporphyrin dependent (CPD) pathway. In the CPD pathway, coproporphyrinogen III is oxidized to coproporphyrin, followed by iron insertion into the tetrapyrrole, forming coproheme1. The final step of the CPD pathway is the decarboxylation of coproheme to heme by the enzyme, coproheme decarboxylase (ChdC)2. The CPD pathway is exclusively found in firmicutes and actinobacteria, both of which are pathogenic and highly antibiotic resistant bacteria that contribute to human disease3. The investigation into the mechanism of the penultimate enzyme in the CPD pathway, ChdC, will assist in the development of new antimicrobial compounds. References Dailey HA, Dailey TA, Gerdes S, Jahn D, Jahn M, O'Brian MR. 2017. Prokaryotic heme biosynthesis: multiple pathways to a common essential product. Micro Molec Bio Rev. 81(1): 1-62. Dailey HA, Gerdes S, Dailey TA, Burch JS, Phillips JD. 2015. Noncanonical coproporphyrin-dependent bacterial heme biosynthesis pathway that does not us protoporphyrin. PNAS. 112(7): 2210-2215. Dailey HA, Gerdes S. 2015. HemQ: An iron-coproporphyrin oxidative decarboxylase for protoheme synthesis in firmicutes and actinobacteria. Arch Biochem Biophys. 574: 27-35.