title: Novel nirK cluster genes in Nitrosomonas europaea are required for NirK-dependent tolerance to nitrite.
abstract: Nitrite reductase (NirK) of Nitrosomonas europaea confers tolerance to nitrite (NO2-). The nirK gene is clustered with three genes of unknown physiological function: ncgABC. At present, this organization is unique to nitrifying bacteria. Here we report that the ncgABC gene products facilitate NirK-dependent NO2- tolerance by reversing the negative physiological effect that is associated with the activity of NirK in their absence. We hypothesize that the ncg gene products are involved in the detoxification of nitric oxide that is produced by NirK.
authors.affiliation: Evolutionary Genetics and Microbial Ecology Laboratory, School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand. h.beaumont@auckland.ac.nz
authors.forename: Hubertus J E
authors.initials: HJ
authors.lastname: Beaumont
authors.forename: Sylvia I
authors.initials: SI
authors.lastname: Lens
authors.forename: Hans V
authors.initials: HV
authors.lastname: Westerhoff
authors.forename: Rob J M
authors.initials: RJ
authors.lastname: van Spanning
mesh_terms: D005798:Genes, Bacterial / Q000502:physiology; D005810:Multigene Family / Q000502:physiology*; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism; D009572:Nitrite Reductases / Q000235:genetics* / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism*; D043370:Nitrosomonas europaea / Q000235:genetics* / Q000378:metabolism*; D009876:Operon / Q000502:physiology; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism
chemical_list: D009573:Nitrites; D009569:Nitric Oxide; D010088:Oxidoreductases; C024748:copper oxidase; D009572:Nitrite Reductases