The chemical steps in an important cellular modification process that adds a chemical tag to some RNAs have been revealed in a new study. Interfering with this process in humans can lead to neuronal diseases, diabetes, and cancers. A research team, led by chemists at Penn State, has imaged a protein that facilitates this RNA modification in bacteria, allowing the researchers to reconstruct the process. A paper describing the modification process appears Sept. 15 in the journal Nature.