This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow An erratum has been published
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hall, S. J.
Right arrow Articles by Kelly, D. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hall, S. J.
Right arrow Articles by Kelly, D. J.

 Previous Article  |  Next Article 

Journal of Bacteriology, December 2008, p. 8075-8085, Vol. 190, No. 24
0021-9193/08/$08.00+0     doi:10.1128/JB.00821-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

A Multicopper Oxidase (Cj1516) and a CopA Homologue (Cj1161) Are Major Components of the Copper Homeostasis System of Campylobacter jejuni{triangledown}

Stephen J. Hall,1 Andrew Hitchcock,1 Clive S. Butler,2 and David J. Kelly1*

Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom,1 School of Biosciences, Centre for Biocatalysis, University of Exeter, Stocker Road, Exeter EX4 4QD, United Kingdom2

Received 11 June 2008/ Accepted 6 October 2008

Metal ion homeostasis mechanisms in the food-borne human pathogen Campylobacter jejuni are poorly understood. The Cj1516 gene product is homologous to the multicopper oxidase CueO, which is known to contribute to copper tolerance in Escherichia coli. Here we show, by optical absorbance and electron paramagnetic resonance spectroscopy, that purified recombinant Cj1516 contains both T1 and trinuclear copper centers, which are characteristic of multicopper oxidases. Inductively coupled plasma mass spectrometry revealed that the protein contained approximately six copper atoms per polypeptide. The presence of an N-terminal "twin arginine" signal sequence suggested a periplasmic location for Cj1516, which was confirmed by the presence of p-phenylenediamine (p-PD) oxidase activity in periplasmic fractions of wild-type but not Cj1516 mutant cells. Kinetic studies showed that the pure protein exhibited p-PD, ferroxidase, and cuprous oxidase activities and was able to oxidize an analogue of the bacterial siderophore anthrachelin (3,4-dihydroxybenzoate), although no iron uptake impairment was observed in a Cj1516 mutant. However, this mutant was very sensitive to increased copper levels in minimal media, suggesting a role in copper tolerance. This was supported by increased expression of the Cj1516 gene in copper-rich media. A mutation in a second gene, the Cj1161c gene, encoding a putative CopA homologue, was also found to result in copper hypersensitivity, and a Cj1516 Cj1161c double mutant was found to be more copper sensitive than either single mutant. These observations and the apparent lack of alternative copper tolerance systems suggest that Cj1516 (CueO) and Cj1161 (CopA) are major proteins involved in copper homeostasis in C. jejuni.

* Corresponding author. Mailing address: Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom. Phone: 44 114 222 4414. Fax: 44 114 272 8697. E-mail: d.kelly{at}sheffield.ac.uk

{triangledown} Published ahead of print on 17 October 2008.

Journal of Bacteriology, December 2008, p. 8075-8085, Vol. 190, No. 24
0021-9193/08/$08.00+0     doi:10.1128/JB.00821-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Nawapan, S., Charoenlap, N., Charoenwuttitam, A., Saenkham, P., Mongkolsuk, S., Vattanaviboon, P. (2009). Functional and Expression Analyses of the cop Operon, Required for Copper Resistance in Agrobacterium tumefaciens. J. Bacteriol. 191: 5159-5168 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»