RNA-Iron complexes catalyse prebiotic oxygen generation

Abstract

The emergence of molecular oxygen on early Earth is conventionally attributed to the evolution of oxygenic photosynthesis. A persistent challenge for early life, however, was the management of reactive oxygen species such as hydrogen peroxide (H₂O₂), which could arise through a variety of abiotic processes. Here we report that some RNA molecules, when coordinated with ferrous iron (Fe²⁺), catalyze the oxidation of H₂O₂ into O₂ and H₂O under anoxic conditions that mimic the early Earth environment. This previously unrecognized RNA-based redox activity suggests that ancient RNA-metal complexes may have contributed to the detoxification of H₂O₂ and the management of oxidative stress prior to the evolution of protein enzymes. Such RNA-Fe complexes provide a plausible molecular mechanism linking early geochemical oxidants to primitive biological redox chemistry.