Table 2.
Identification of nine selected nitrogen fixation-inducible genes and nitrogenase activity of the corresponding mutant strains
| Gene ID | Functional description | Involvement in nitrogen fixation in other systems | Nitrogenase activitya, % |
|---|---|---|---|
| PST0446 | Cytoplasmic membrane protein | Unknown | 64 |
| PST0874 | Chemotactic transducer | Unknown | 52 |
| PST1325 | conserved hypothetical protein | Unknown | 23 |
| PST1521 | outer membrane protein | Unknown | 68 |
| PST2508 | methyl-accepting chemotaxis transducer | Unknown | 92 |
| PST3417 | predicted transcriptional regulators | Unknown | 58 |
| PST3422 | outer membrane protein | Unknown | 96 |
| PST3621 | transcriptional regulator, AraC family | Unknown | 80 |
| PST4084 | ABC-type amino acid transport/signal transduction systems | Unknown | 54 |
aNitrogenase activity of nine non-polar mutants (enabling transcription of downstream genes) is expressed as % of wild type A1501 activity, which is in the range of 1645 ± 169 nmol ethylene/min/mg protein. Nitrogenase activity was examined under nitrogen fixation conditions (0.1 mM ammonium and 0.5% oxygen tension). Data are expressed as the means of three independent experiments.