This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Saunders, N. F. W. Articles by van Spanning, R. J. M. Search for Related Content PubMed PubMed Citation Articles by Saunders, N. F. W. Articles by van Spanning, R. J. M.

Journal of Bacteriology, September 2000, p. 5211-5217, Vol. 182, No. 18
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

The NosX and NirX Proteins of Paracoccus denitrificans Are Functional Homologues: Their Role in Maturation of Nitrous Oxide Reductase

Neil F. W. Saunders,^1, Jorrit J. Hornberg,¹ Willem N. M. Reijnders,¹ Hans V. Westerhoff,¹ Simon de Vries,² and Rob J. M. van Spanning^1,*

Department of Molecular Cell Physiology, Faculty of Biology, BioCentrum Amsterdam, Vrije Universiteit, De Boelelaan 1087, NL-1081 HV Amsterdam,¹ and Department of Biotechnology, Delft University of Technology, Delft,² The Netherlands, European Union

Received 3 April 2000/Accepted 15 June 2000

The nos (nitrous oxide reductase) operon of Paracoccus denitrificans contains a nosX gene homologous to those found in the nos operons of other denitrifiers. NosX is also homologous to NirX, which is so far unique to P. denitrificans. Single mutations of these genes did not result in any apparent phenotype, but a double nosX nirX mutant was unable to reduce nitrous oxide. Promoter-lacZ assays and immunoblotting against nitrous oxide reductase showed that the defect was not due to failure of expression of nosZ, the structural gene for nitrous oxide reductase. Electron paramagnetic resonance spectroscopy showed that nitrous oxide reductase in cells of the double mutant lacked the Cu_A center. A twin-arginine motif in both NosX and NirX suggests that the NosX proteins are exported to the periplasm via the TAT translocon.

---

^* Corresponding author. Mailing address: Department of Molecular Cell Physiology, Faculty of Biology, BioCentrum Amsterdam, Vrije Universiteit, De Boelelaan 1087, NL-1081 HV Amsterdam, The Netherlands. Phone: 31 20 4447179. Fax: 31 20 4447229. E-mail: spanning{at}bio.vu.nl.

Present address: School of Microbiology and Immunology, University of New South Wales, Sydney 2052, New South Wales, Australia.

---

Journal of Bacteriology, September 2000, p. 5211-5217, Vol. 182, No. 18
0021-9193/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

This article has been cited by other articles:

• Loo, C. Y., Mitrakul, K., Jaafar, S., Gyurko, C., Hughes, C. V., Ganeshkumar, N. (2004). Role of a nosX Homolog in Streptococcus gordonii in Aerobic Growth and Biofilm Formation. J. Bacteriol. 186: 8193-8206 [Abstract] [Full Text]  
• Skovran, E., Lauhon, C. T., Downs, D. M. (2004). Lack of YggX Results in Chronic Oxidative Stress and Uncovers Subtle Defects in Fe-S Cluster Metabolism in Salmonella enterica. J. Bacteriol. 186: 7626-7634 [Abstract] [Full Text]  
• Honisch, U., Zumft, W. G. (2003). Operon Structure and Regulation of the nos Gene Region of Pseudomonas stutzeri, Encoding an ABC-Type ATPase for Maturation of Nitrous Oxide Reductase. J. Bacteriol. 185: 1895-1902 [Abstract] [Full Text]  
• Wunsch, P., Herb, M., Wieland, H., Schiek, U. M., Zumft, W. G. (2003). Requirements for CuA and Cu-S Center Assembly of Nitrous Oxide Reductase Deduced from Complete Periplasmic Enzyme Maturation in the Nondenitrifier Pseudomonas putida. J. Bacteriol. 185: 887-896 [Abstract] [Full Text]  
• Skovran, E., Downs, D. M. (2003). Lack of the ApbC or ApbE Protein Results in a Defect in Fe-S Cluster Metabolism in Salmonella enterica Serovar Typhimurium. J. Bacteriol. 185: 98-106 [Abstract] [Full Text]