TABLE 2.
Determination of iron, molybdenum, and vanadium content in FeFe proteins coming from the different genetic backgroundsa
| FeFe protein | Metal content (mol/mol protein) |
||
|---|---|---|---|
| Iron | Molybdenum | Vanadium | |
| DJ2241 | 26 ± 1.7 | 0.02 ± 0.01 | 0.06 ± 0.03 |
| DJ2303 (ΔnifE) | 26 ± 1.6 | 0.01 ± 0.01 | 0.09 ± 0.08 |
| DJ2381 (ΔvnfEN) | 28 ± 0.9 | 0.01 ± 0.01 | 0.09 ± 0.07 |
| DJ2387 (ΔnifE ΔvnfEN) | 29 ± 2.5 | 0.004 ± 0.002 | 0.10 ± 0.08 |
| DJ2245 (ΔnifB) | 15 ± 0.6 | 0.001 ± 0.001 | 0.03 ± 0.05 |
a
Metal contents were quantified by ICP-MS. Molar ratios were calculated based on the molecular weight of the FeFe protein α2β2δ2 complex, or α2β2 complex in the case of the strain inactivated for NifB. Data presented are the average from at least two independent determinations.