title: Nitrite reductase of Nitrosomonas europaea is not essential for production of gaseous nitrogen oxides and confers tolerance to nitrite.
abstract: A gene that encodes a periplasmic copper-type nitrite reductase (NirK) was identified in Nitrosomonas europaea. Disruption of this gene resulted in the disappearance of Nir activity in cell extracts. The nitrite tolerance of NirK-deficient cells was lower than that of wild-type cells. Unexpectedly, NirK-deficient cells still produced nitric oxide (NO) and nitrous oxide (N(2)O), the latter in greater amounts than that of wild-type cells. This demonstrates that NirK is not essential for the production of NO and N(2)O by N. europaea. Inactivation of the putative fnr gene showed that Fnr is not essential for the expression of nirK.
authors.affiliation: BioCentrum Amsterdam, Department of Molecular Cell Physiology, Vrije Universiteit, NL-1081 Amsterdam, The Netherlands.
authors.forename: Hubertus J E
authors.initials: HJ
authors.lastname: Beaumont
authors.forename: Norman G
authors.initials: NG
authors.lastname: Hommes
authors.forename: Luis A
authors.initials: LA
authors.lastname: Sayavedra-Soto
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Arp
authors.forename: David M
authors.initials: DM
authors.lastname: Arciero
authors.forename: Alan B
authors.initials: AB
authors.lastname: Hooper
authors.forename: Hans V
authors.initials: HV
authors.lastname: Westerhoff
authors.forename: Rob J M
authors.initials: RJ
authors.lastname: van Spanning
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D015870:Gene Expression; D007506:Iron-Sulfur Proteins / Q000172:deficiency / Q000235:genetics; D009572:Nitrite Reductases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D009589:Nitrogen Oxides / Q000378:metabolism*; D009606:Nitrosomonas / Q000201:enzymology* / Q000235:genetics; D009609:Nitrous Oxide / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; D009573:Nitrites; D009589:Nitrogen Oxides; D009572:Nitrite Reductases; C052695:nitrite reductase, copper-containing; D009609:Nitrous Oxide