The nitrate- and nitrite sensing domain (NIT) is found in receptor components of signal transducing pathways in bacteria which control gene expression, cellular motility and enzyme activity in response to nitrate and nitrite concentrations. The NIT domain is predicted to be all alpha-helical in structure [1].

1: The NIT domain: a predicted nitrate-responsive module in bacterial sensory receptors. Shu CJ, Ulrich LE, Zhulin IB; Trends Biochem Sci 2003;28:121-124. PMID:12633990