Proc. Natl. Acad. Sci. USA doi:10.1073/pnas.0911209107 (2010)

The ability to selectively control gene expression has a wealth of applications in biomedical research. Riboswitches are a promising tool; they are a portion of a messenger RNA (which is translated to generate a protein) that can bind to a small molecule to regulate the RNA's activity.

Jason Micklefield and his colleagues at the University of Manchester, UK, have developed riboswitches that, unlike naturally occurring counterparts, respond to synthetic small molecules but not to natural ones. This potentially enables greater gene control.

The authors introduced their switch into Escherichia coli and used it to induce greater gene expression by adding higher concentrations of a synthetic small molecule. They also generated mutated versions of their riboswitches that could induce low, medium or high levels of protein production.