Riboswitch: Ancient living switch for gene regulation

Since last two decades, the role of structural fluctuations of RNA molecules have emerged as one of the key aspects for gene expression in bacteria and they have been found to play very crucial roles for survival of bacteria under highly fluctuating environmental conditions. Riboswitches are one of the RNA elements located in the 5′ region of bacterial mRNA controlling the expression of a gene located downstream to it, by conformational changes of its own upon selective binding to ligands. These molecular fossils are probably the most ancient regulatory system for gene expression. Association of riboswitches with bacterial pathogenesis and other related functions has attracted their exploitation as potential drug targets. Natural as well as synthetic riboswitches hold considerable potential to be the next generation gene control systems to be used in the field of molecular biology and genetic engineering.