Function
Transcription regulator that actives the transcription of genes required for nitrogen assimilation such as nrgAB (ammonium transport), nasABCDEF (nitrate/nitrite assimilation), ureABC (urea degradation) and gabP (GABA transport), during nitrogen limitation (PubMed:8799114, PubMed:9603886, PubMed:10231480, PubMed:10864496, PubMed:11719184, PubMed:12823818). Also represses glnRA and gltAB in the absence of ammonium (PubMed:8799114, PubMed:9603886, PubMed:10231480, PubMed:10864496, PubMed:11719184, PubMed:12823818). On the contrary of the MerR members, which require longer DNA sites for high-affinity binding, TnrA requires a DNA sequence of 17 nucleotides as minimal binding site (PubMed:10231480, PubMed:25691471).