Figure 4

Effect of oxidation on Ku mutant structure. Following oxidation and re-reduction as described in the legend to Figure 3, wild type Ku (4 μg) and Ku70/80ΔC (4 μg) were subjected to limited tryptic cleavage. Diamide was added after the addition of DTT to the control reactions while reduced conditions were first oxidized with diamide then re-reduced with DTT. Reactions were terminated by the addition of SDS sample buffer and products separated by SDS-PAGE and visualized via staining with Coomassie Blue.