The NIT domain: a predicted nitrate-responsive module in bacterial sensory receptors.

A nitrate- and nitrite-sensing (NIT) domain as found in the NasR protein, has been detected in various receptor components of signal transduction pathways in different bacterial lineages. Cellular functions controlled by receptors that contain this novel domain include regulation of gene expression (transcription anti-terminators and histidine kinases), cell motility (chemotaxis receptors) and enzyme activity (diguanylate cyclases and phosphodiesterases).