Atomic resolution mechanistic studies of ribocil: A highly selective unnatural ligand mimic of the E. coli FMN riboswitch.
Howe, J.A., Xiao, L., Fischmann, T.O., Wang, H., Tang, H., Villafania, A., Zhang, R., Barbieri, C.M., Roemer, T.(2016) RNA Biol 13: 946-954
- PubMed: 27485612
- DOI: https://doi.org/10.1080/15476286.2016.1216304
- Primary Citation of Related Structures:
5KX9 - PubMed Abstract:
Bacterial riboswitches are non-coding RNA structural elements that direct gene expression in numerous metabolic pathways. The key regulatory roles of riboswitches, and the urgent need for new classes of antibiotics to treat multi-drug resistant bacteria, has led to efforts to develop small-molecules that mimic natural riboswitch ligands to inhibit metabolic pathways and bacterial growth. Recently, we reported the results of a phenotypic screen targeting the riboflavin biosynthesis pathway in the Gram-negative bacteria Escherichia coli that led to the identification of ribocil, a small molecule inhibitor of the flavin mononucleotide (FMN) riboswitch controlling expression of this biosynthetic pathway. Although ribocil is structurally distinct from FMN, ribocil functions as a potent and highly selective synthetic mimic of the natural ligand to repress riboswitch-mediated ribB gene expression and inhibit bacterial growth both in vitro and in vivo. Herein, we expand our analysis of ribocil; including mode of binding in the FMN binding pocket of the riboswitch, mechanisms of resistance and structure-activity relationship guided efforts to generate more potent analogs.
Organizational Affiliation:
a Merck Research Laboratories , Kenilworth , NJ , USA.