Table 1.

Main contributors of nitrogen metabolism in Bacillus.

Transcription factors or enzyme	Metabolites sensed	Mediator	Function
TnrA	Glutamine	Glutamine synthetase–glutamine complex interacts with TnrA	Activate many nitrogen-metabolism genes
GltC	2-oxoglutarate; Glutamate	Glutamate dehydrogenase	Activate gltAB operon
Glutamine synthetase	Glutamine; NH4+	None	Trigger enzyme
GlnK	ATP and 2-oxoglutarate	None	Sensor of energy state and control NH4+ absorption
GlnR	Glutamine	Glutamine synthetase	Inactivate glnRA, ureABC and tnrA
CodY	GTP and BCAAs	None	Activate many carbon‑and nitrogen‑metabolizing genes

BCAAs: branched‑chain amino acids.