Flavin mononucleotide riboswitch (FMN riboswitch) (FMN riboswitch)

The Flavin mononucleotide (FMN) riboswitch is a highly conserved regulatory RNA element located in the 5' untranslated region of bacterial mRNAs, primarily those involved in riboflavin (vitamin B2) biosynthesis and transport (Serganov et al., Nature, 2009). It functions as a metabolite-sensing genetic switch that directly binds FMN with high affinity, triggering a conformational change that modulates gene expression through Rho-independent transcription termination or inhibition of translation initiation (Winkler et al., PNAS, 2002). This riboswitch is essential for maintaining riboflavin homeostasis in many pathogenic bacteria, including Staphylococcus aureus and Bacillus subtilis, making it a critical survival factor (Howe et al., Nature, 2015). Because riboswitches are prevalent in bacteria but absent in the human genome, they represent a promising class of targets for the development of novel, highly specific antibacterial agents (Blount & Breaker, Nature Biotechnology, 2006). Small molecules like Ribocil and its derivatives have been identified as potent inhibitors that mimic FMN, binding to the riboswitch to repress essential metabolic pathways and effectively halt bacterial growth (Vicens et al., Frontiers in Genetics, 2018).

Other names

RFN elementRiboflavin riboswitchribB riboswitch

Ligand-induced conformational change in the RNA aptamer domain that triggers premature transcription termination or prevents translation initiation of downstream genes.