Nitrite reductase of Nitrosomonas europaea is not essential for production of gaseous nitrogen oxides and confers tolerance to nitrite.
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.
Beaumont
Hubertus J E
HJ
BioCentrum Amsterdam, Department of Molecular Cell Physiology, Vrije Universiteit, NL-1081 Amsterdam, The Netherlands.
Hommes
Norman G
NG
Sayavedra-Soto
Luis A
LA
Arp
Daniel J
DJ
Arciero
David M
DM
Hooper
Alan B
AB
Westerhoff
Hans V
HV
van Spanning
Rob J M
RJ
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
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