Table 1.
Aconitase activity and mitochondrial iron content
| Strain | No iron* | 5 μM iron* | |||
|---|---|---|---|---|---|
| Aconitase† | Mitochondrial iron‡ (nmol/mg protein) | Aconitase† | |||
| Wild type | 100 | 15±7 | 100 | ||
| D86K | 93±3 | 27±2 | 70±7 | ||
| E89K | 81±5 | 49±4 | 55±8 | ||
| D101A | 95±2 | 21±5 | 73±8 | ||
| D86A/E89A | 90±2 | 22±2 | 75±3 | ||
| D86K/E89K | 31±8 | 82±10 | 18±6 | ||
| D101K/E103K | 34±6 | 75±8 | 20±5 | ||
| D86A/E89A/D101A/E103A | 30±6 | 81±7 | 17±6 | ||
| Δyfh1 | 19±5 | 82±8 | 14±6 | ||
*Assays were performed with mitochondrial extracts from cells grown in raffinose synthetic medium in the absence or in the presence of 5 μM FeSO4. The data are averages obtained from several cultures of two independently isolated transformants.
†Aconitase activity was normalized to isocitrate dehydrogenase activity and expressed as a percentage of the control value of each experiment.
‡Free iron was measured using bathophenantroline sulphonate in the presence of dithionite (Foury & Cazzalini, 1997).