In vitro and in vivo effects of oxidative damage to deoxyguanosine.

Biochemical, biophysical and biological studies of oligonucleotides containing lesions at defined sites provide a molecular basis for the effects of DNA lesions. dG (deoxyguanosine) is the most easily oxidized of the four native nucleotides. The chemical reactivity of dG correlates with compilations of mutations, which reveal that a significant fraction of transitions or transversions involve dG. OxodG (7,8-dihydro-8-hydroxy-2'-deoxyguanosine) is widely recognized as an important lesion derived from the oxidation of dG, and significant effort has been expended in studies of its effects on DNA structure and function. Recently, the properties of other lesions derived from dG and/or the oxidation of OxodG have been uncovered. Studies on these lesions reveal that they too are biologically significant.