RNA−Iron complexes catalyse prebiotic oxygen generation

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. Reactive oxygen species such as hydrogen peroxide (H₂O₂) could have arisen through abiotic processes on the early Earth and been considered a source of oxidative stress for early life. Here, the authors reveal that RNA molecules coordinated with ferrous iron can catalyze the conversion of H2O2 into O2 and H2O under anoxic conditions, suggesting RNA-metal complexes played a crucial role in managing oxidative stress before protein enzymes evolved.