Cover Feature: Mechanistic Insights Into the Oxidative Reactivity of 2‐Selenouridine in tRNA

A distinct oxidative behavior of selenium in proteins and RNA is observed in the presence of glutathione. In proteins, oxidized selenocysteine residues are reversibly reduced by GSH, whereas oxidation of 2-selenouridine in RNA proceeds via transient acidic selenium species acting as leaving groups, to yield irreversible products. These products result from nucleophilic substitution at C2 (e.g., by GSH) and selenium elimination. These findings indicate distinct roles for selenium in proteins vs tRNA and suggest that oxidative activation of tRNA modifications might regulate translation and stress responses. More details are provided in the Research Article by K. Kulik, B. Nawrot, and co-workers (DOI: 10.1002/chem.71130).