Anaerobic nitric oxide reductase; uses NADH to detoxify nitric oxide (NO), protecting several 4Fe-4S NO-sensitive enzymes. Has at least 2 reductase partners, only one of which (NorW, flavorubredoxin reductase) has been identified. NO probably binds to the di-iron center; electrons enter from the reductase at rubredoxin and are transferred sequentially to the FMN center and the di-iron center. Also able to function as an aerobic oxygen reductase. Binds 3 Fe cations per monomer. Binds 1 FMN per monomer. Nitrogen metabolism; nitric oxide reduction. Homotetramer. Submicromolar concentrations of NO induce NorV-dependent NO consumption; as NO reductase is sensitive to oxygen, no activity is detected in its presence. Repressed by oxygen in the presence of NO. Different effects on anaerobic induction in the absence of NO, and in the presence of N(O)3- or N(O)2- have been reported. Transcription is negatively regulated by FNR and does not require NarL or NarP. In the N-terminal section; belongs to the zinc metallo-hydrolase group 3 family.