Repair of oxidative DNA damage--an important factor reducing cancer risk. Minireview.

Oxygen free radicals formed during normal aerobic cellular metabolism generate a variety of DNA lesions including modified bases, abasic sites and single strand breaks with blocked 3' termini. If left unrepaired, these damages may contribute to a number of degenerative processes, including cancer and aging. In most organisms, the repair of oxidative DNA lesions is supposed to be handled by the base excision repair (BER) pathway. BER is a multistep process that involves the sequential activity of several proteins, many of them were isolated and functionally characterized using the simple prokaryotic and lower eukaryotic model systems, Escherichia coli and Saccharomyces cerevisiae, respectively. As the amino acid sequence of DNA repair proteins is often well conserved from bacteria to man, our understanding of BER in higher eukaryotes drives extensively from the microbial models, namely from the yeast S. cerevisiae. Thus, results obtained on a simple yeast model are a source of new information, which can be used as a paradigm for all eukaryotic cells.