RNA polymerase factor sigma-54; Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is responsible for the expression of the nitrogen fixation genes. The open complex (sigma-54 and core RNA polymerase) serves as the receptor for receipt of the melting signal from the remotely bound activator protein NifA for the expression of the nitrogen fixation proteins.

Nitrogen fixation protein NifB; Involved in the biosynthesis of the iron-molybdenum cofactor (FeMo-co or M-cluster) found in the dinitrogenase enzyme of the nitrogenase complex in nitrogen-fixing microorganisms. NifB catalyzes the crucial step of radical SAM-dependent carbide insertion that occurs concomitant with the insertion of a 9th sulfur and the rearrangement/coupling of two [4Fe-4S] clusters into a [8Fe-9S-C] cluster, the precursor to the M-cluster.

Nitrogen regulation protein NR(II); Member of the two-component regulatory system NtrB/NtrC, which controls expression of the nitrogen-regulated (ntr) genes in response to nitrogen limitation. Under conditions of nitrogen limitation, NtrB autophosphorylates and transfers the phosphoryl group to NtrC. In the presence of nitrogen, acts as a phosphatase that dephosphorylates and inactivates NtrC.

Nitrogenase reductase; The key enzymatic reactions in nitrogen fixation are catalyzed by the nitrogenase complex, which has 2 components: the iron protein and the molybdenum-iron protein; Belongs to the NifH/BchL/ChlL family.

Nitrogen regulatory protein P-II 1; Indirectly regulates nitrogen metabolism; at high nitrogen levels P-II prevents the phosphorylation of NR-I, the transcriptional activator of the glutamine synthetase gene (glnA); at low nitrogen levels P-II is uridylylated to form PII-UMP and interacts with an adenylyltransferase (GlnE) that activates GlnA; Derived by automated computational analysis using gene prediction method: Protein Homology.

Iron-molybdenum cofactor biosynthesis protein NifQ; Derived by automated computational analysis using gene prediction method: Protein Homology.

Ammonium transporter; Derived by automated computational analysis using gene prediction method: Protein Homology.

Nitrogen regulatory protein P-II 1; In nitrogen-limiting conditions, when the ratio of Gln to 2- ketoglutarate decreases, P-II is uridylylated to P-II-UMP. P-II-UMP allows the deadenylation of glutamine synthetase (GS), thus activating the enzyme. Conversely, in nitrogen excess P-II is deuridylated and promotes the adenylation of GS. P-II indirectly controls the transcription of the GS gene (glnA). P-II prevents NR-II-catalyzed conversion of NR-I to NR-I-phosphate, the transcriptional activator of glnA. When P-II is uridylylated to P-II-UMP, these events are reversed; Belongs to the P( [...]

Aerobic respiration control sensor protein ArcB; Sensor-regulator protein which regulates the expression of many genes in response to respiratory growth conditions including anaerobic repression of the arc modulon; hybrid sensory histidine kinase in two-component regulatory system with ArcA; Derived by automated computational analysis using gene prediction method: Protein Homology.