Thiamine pyrophosphate riboswitch (TPP riboswitch) (TPP riboswitch)

The thiamine pyrophosphate (TPP) riboswitch is a highly conserved non-coding RNA element located within the 5' untranslated region of messenger RNA that regulates gene expression in response to TPP concentrations (Winkler et al., 2002). It is the most widely distributed riboswitch class, found across bacteria, archaea, and some eukaryotes like plants and fungi (Sudarsan et al., 2003). The riboswitch consists of a sensing aptamer domain that binds TPP with high affinity and an expression platform that undergoes conformational changes to modulate transcription or translation (Serganov et al., 2006). In bacteria, TPP binding typically leads to the downregulation of genes involved in thiamine biosynthesis and transport, serving as a critical feedback mechanism for metabolic homeostasis (Blount & Breaker, 2006). Because TPP riboswitches are essential for the survival of many pathogenic bacteria and lack direct human homologs, they are considered promising targets for novel antimicrobial therapies (Warner et al., 2014). Small molecule analogs such as pyrithiamine have been shown to bind these riboswitches, effectively suppressing bacterial growth by mimicking the natural ligand and permanently switching off vital metabolic pathways (Sudarsan et al., 2005).

Other names

Thi-box riboswitchTHI-elementTPP-sensing riboswitch

Ligand-induced conformational change in the mRNA leader sequence leading to transcriptional attenuation or translational inhibition (Winkler et al., 2002).