N-Acylated Derivatives of Sulfamethoxazole Block Chlamydia Fatty Acid Synthesis and Interact with FabF

The type II fatty acid synthesis (FASII) pathway is essential for bacterial lipid biosynthesis and continues to be a promising target for novel antibacterial compounds. Recently, it has been demonstrated that is capable of FASII and this pathway is indispensable for growth. Previously, a high-content screen with -infected cells was performed, and acylated sulfonamides were identified to be potent growth inhibitors of the bacteria. strains resistant to acylated sulfonamides were isolated by serial passage of a wild-type strain in the presence of low compound concentrations. Results from whole-genome sequencing of 10 isolates from two independent drug-resistant populations revealed that mutations that accumulated in were predominant. Studies of the interaction between the FabF protein and small molecules showed that acylated sulfonamides directly bind to recombinant FabF and treatment of -infected HeLa cells with the compounds leads to a decrease in the synthesis of fatty acids. This work demonstrates the importance of FASII for development and may lead to the development of new antimicrobials.