A Hot Spot for Hydrogen Peroxide-Induced Damage in the Human Hypoxia-Inducible Factor 1 Binding Site of thePGK 1Gene

Using ligation-mediated polymerase chain reaction to separately map the distribution of induced oxidized bases and strand breaks along the humanPGK1promoter at nucleotide resolution, we previously described the pattern of oxidative DNA damage inducedin vitroby Cu(II)/ascorbate/H2O2[J. Biol. Chem.270, 17633–17640 (1995)]. Here we report that the pattern ofin vivobase damage caused by H2O2is almost identical to that of the previously usedin vitrosystem with the exception of transcription factor-associated footprints. An unusually strong positive footprint for both strand breaks and oxidized bases is associated with binding of the hypoxia-inducible transcription factor-1. Base damage at this footprint was 52–91% repaired in 24 h, which was similar to the global base damage repair rate. However, strand breaks at this footprint were only 39–55% repaired in 24 h or approximately 100-fold slower than the global strand break repair rate.