|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions → Protein-Modification Reactions|
|Reactions Classified By Substrate → Macromolecule Reactions → Protein-Reactions → Protein-Modification Reactions|
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Mass balance status: Balanced.
In the presence of nitrate, nitrate/nitrite response regulator NarL is phosphorylated by the sensor kinase-phosphotransferase NarX. In the presence of nitrite, the NarL protein is dephosphorylated with the sensor protein NarX acting as a phospho-NarL phosphatase.
In the presence of nitrate the nitrate/nitrite response regulator NarL can be phosphorylated by both nitrate/nitrite sensor kinase-phosphotransferases phospho-NarX and phospho-NarQ. In this activated state phospho-NarL can act as both an activator of nitrate and nitrite reductase transcription and repressor of fumarate reductase transcription. Both actions switch anaerobic respiration to utilization of either nitrate or nitrite as electron acceptors. In the presence of nitrite the NarL protein is phosphorylated only by phospho-NarQ. The sensor protein NarX acts as a phospho-NarL phosphatase under these conditions, countering the sensor protein NarQ phosphorylation to some extent. [Hoch95, Walker93, Egan91]
Walker93: Walker MS, DeMoss JA (1993). "Phosphorylation and dephosphorylation catalyzed in vitro by purified components of the nitrate sensing system, NarX and NarL." J Biol Chem 1993;268(12);8391-3. PMID: 8473280
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