A prebiotic role for 8-oxoguanosine as a flavin mimic in pyrimidine dimer photorepair.

Redox-active enzyme cofactors derived from ribonucleotides have been called "fossils of the RNA world," suggesting that early catalysts employed modified nucleobases to facilitate redox chemistry in primitive metabolism. Here, we show that the common oxidative damage product 8-oxo-7,8-dihydroguanine (OG), when incorporated into a DNA or RNA strand in… (More)