Stimulation of DNA Glycosylase Activities by XPC Protein Complex: Roles of Protein-Protein Interactions
Figure 5
The effect of XPC on the activity of SUMO-1-modified TDG that cleaves uracil from G/U mismatches. (a) Silver staining of the purified recombinant nonmodified His-TDG and SUMO-1-modified His-TDG. M represents the size marker. (b) The sumoylation of TDG was verified with western blot analyses using anti-TDG antibody (left) or anti-SUMO-1 antibody (right). (c) The activity of sumoylated His-TDG was measured by using 1.6 nM of 60-bp DNA containing a single G/U mismatch as a substrate. The reaction was done at C for the time indicated with 2 nM SUMO-1-conjugated His-TDG in the presence of XPC-RAD23B. The DNA samples were then purified and subjected to alkali-treatment to cleave the resulting AP sites and separated with denaturing PAGE. The ratio of the cleaved product was calculated and plotted as a graph. The mean values and standard errors were calculated from at least two independent experiments.
