Novel riboswitch measures glycine

RNA self-regulation is as complex and sophisticated as protein-based gene regulation, according to a report in Science this week. A novel Bacillus subtilis riboswitch as described by the authors is an efficient and highly sophisticated on or off control mechanism, with a key regulatory role of switching between burning glycine for energy and using it for protein synthesis.

The riboswitch is the first example of a riboswitch that involves complex binding interactions comparable to multiple protein interactions, according to Ronald R. Breaker's group at Yale University, and is the only one so far discovered that switches on gene expression if activated instead of responding in a simple negative-feedback fashion to levels of their target compound.

The riboswitch has two domains that bind to glycine, while all other riboswitches only have one binding domain, Breaker said. "Binding of one ligand at one binding site improves the binding affinity of the second ...