Prevention of 8OG-induced G:C-T:A transversion mutations. The 8OG base is one of the major forms of oxidative DNA damage and can be generated by reactive oxygen species. Since 8OG can pair not only with C but also with A, it causes a G:C-T:A transversion through DNA replication. MutM (OGG1)- and MutY (MYH)-dependent base-excision repair pathways are known to remove the 8OG and A from 8OG:C and 8OG:A pairs, respectively. MMR is also responsible for the removal of A from 8OG.
