Table 1:
ATPase stimulation in the presence of [2Fe-2S](GS)4 and GSH. Stimulation of ATPase activity of Atm1p variants was measured in the presence of glutathione and [2Fe-2S](GS)4 cluster. In the cases where stimulation was observed, the apparent KD for cluster or glutathione binding was calculated based on the substrate dependence curve. The extent of stimulation reflects the relative change in Michaelis-Menten profiles for ATPase activity in the presence or absence of possible transporter substrates. nd – could not be determined in the absence of stimulation.
| GSH stimulation | GSH KD | cluster stimulation | cluster KD | |
|---|---|---|---|---|
| Wild-Type | 0.54 ± 0.03 μM/min | 32 ± 9 μM | 0.64 ± 0.04 μM/min | 910 ± 60 nM |
| D398A | no stimulation | nd | no stimulation | nd |
| D398E | no stimulation | nd | no stimulation | nd |
| D398K | no stimulation | nd | no stimulation | nd |
| D398N | 0.32 ± 0.01 μM/min | 74 ± 10 μM | 0.36 ± 0.02 μM/min | 5.6 ± 0.8 μM |
| D398R | no stimulation | nd | no stimulation | nd |