HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Juty, N. S. Articles by Hill, S. Search for Related Content PubMed PubMed Citation Articles by Juty, N. S. Articles by Hill, S. Agricola Articles by Juty, N. S. Articles by Hill, S.

The Klebsiella pneumoniae cytochrome bd’ terminal oxidase complex and its role in microaerobic nitrogen fixation

Navtej S. Juty^1,2,

Farhad Moshiri^3,

Department of Biochemistry, University of Southampton, Southampton SO16 7PX, UK
Nitrogen Fixation Laboratory, John Innes Centre, Norwich NR4 7UH, UK
Department of Biology, The Johns Hopkinas University, Baltimore, MD 21218, USA

¹ Author for correspondence: Susan Hill. Tel: +44 1603 456900 ext. 2749. Fax: +44 1603 454970.

ABSTRACT

Summary: Cytochrome bd’ has been implicated in having an important role in microaerobic nitrogen fixation in the enteric bacterium Klebsiella pneumoniae, where it is expressed under all conditions that permit diazotrophy. In this paper the sequence of the genes encoding this terminal oxidase (cydAB) of Klebsiella pneumoniae and the characterization of a cyd mutant are reported. The deduced amino acid sequences support the proposal that His 19, His 186 and Met 393 provide three of the four axial ligands to the Fe of the three haems in the oxidase complex. The nitrogen-fixing ability of the mutant was severely impaired in the presence of low concentrations of oxygen compared with the wild-type bacterium. Only the wild-type organism was capable of microaerobic nitrogenase activity supported by fermentation products. It is proposed that formate dehydrogenase-O may be involved in supplying electrons to a respiratory chain terminated by the bd-type oxidase, which would remove inhibitory oxygen and supply ATP for nitrogenase activity.

Present address: Mail Zone GG4G, gen, A Unit of Monsanto, 700 Chesterfield Parkway, St Louis 63198 USA.

Present address: City of National Medical Center, Division of Pediatrics, 1500 East Duarte Road CA 91010-0269, USA.

This article has been cited by other articles:

				L. Voggu, S. Schlag, R. Biswas, R. Rosenstein, C. Rausch, and F. Gotz Microevolution of Cytochrome bd Oxidase in Staphylococci and Its Implication in Resistance to Respiratory Toxins Released by Pseudomonas. J. Bacteriol., December 1, 2006; 188(23): 8079 - 8086. [Abstract] [Full Text] [PDF]

				J. Zhang, P. Hellwig, J. P. Osborne, and R. B. Gennis Arginine 391 in Subunit I of the Cytochrome bd Quinol Oxidase from Escherichia coli Stabilizes the Reduced Form of the Hemes and Is Essential for Quinol Oxidase Activity J. Biol. Chem., December 24, 2004; 279(52): 53980 - 53987. [Abstract] [Full Text] [PDF]

				H. Cruz-Ramos, G. M. Cook, G. Wu, M. W. Cleeter, and R. K. Poole Membrane topology and mutational analysis of Escherichia coli CydDC, an ABC-type cysteine exporter required for cytochrome assembly Microbiology, October 1, 2004; 150(10): 3415 - 3427. [Abstract] [Full Text] [PDF]

				B. D. Kana, E. A. Weinstein, D. Avarbock, S. S. Dawes, H. Rubin, and V. Mizrahi Characterization of the cydAB-Encoded Cytochrome bd Oxidase from Mycobacterium smegmatis J. Bacteriol., December 15, 2001; 183(24): 7076 - 7086. [Abstract] [Full Text] [PDF]

				L. Winstedt, K.-I. Yoshida, Y. Fujita, and C. von Wachenfeldt Cytochrome bd Biosynthesis in Bacillus subtilis: Characterization of the cydABCD Operon J. Bacteriol., December 15, 1998; 180(24): 6571 - 6580. [Abstract] [Full Text]