Potential Damage to Deoxyguanosine
Deoxyguanosine is a base that is vulnerable to reactive oxygen species (ROS) because of its comparatively lower oxidation potential. As a result, ROS can oxidize dG to make 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). This modification is known as a pre-mutagenic lesion, meaning that the damage can still be repaired, but can lead to a mutation if left alone. The oxidation of dG can be detrimental to the genome since 8-oxodG base pairs with deoxyadenosine (dA) instead of the deoxycytidine (dC), which is the proper Watson-Crick base pair. Consequently, if the lesion is not repaired via the mismatch repair mechanism, during DNA replication a dA will take the place of the dC, resulting in a mutation. Deoxyguanosine is also a base that is prone to reacting with carcinogens, such as polyaromatic hydrocarbons (PAHs). Once the PAHs are metabolized and made stable in the intracellular environment, they can react with dG to form 7-methyldeoxyguanosine or O6-methyldeoxyguanosine. The presence of these modifications can then lead to downstream effects that lower the fidelity of DNA replication and potentially cause mutations. ==See also==