Figure S10. Effect of cadmium on the endonuclease activity of the R406K mutant form of A. aeolicus MutL (aqMutL).

The R406K mutant form of aqMutL (blue) was incubated in the 0.5 mM CdCl₂-containing buffer at 60°C for 0, 3, 6, 12, or 24 h. The endonuclease activity of the CdCl₂-treated protein (5 μM) was measured in the divalent metal-free buffer using a supercoiled plasmid DNA as the substrate at 70°C for 30 min. The relative activity normalized by the activity at 0 h CdCl₂-treatment was plotted against treatment time. For comparison, the result for the WT of aqMutL in Fig 3A is also shown in the same way (cyan). Average values from three independent experiments are shown with standard deviations. Lines indicate theoretical simple exponential curves that were fitted to the data. Rate constants for the WT and R406K mutant forms of aqMutL were 0.12 and 0.13 h⁻¹, respectively, indicating that the rate for the metal replacement was not affected by the mutation.

Source data are available for this figure.