Metabolic role and properties of nitrite reductase of nitrate-ammonifying marine Vibrio species

Rehr, Bert

doi:10.1016/0378-1097(86)90115-1

Cited by 7 publications

(7 citation statements)

References 8 publications

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“…However, the corresponding enzymes or the capability of respiratory nitrite ammonification were characterized in only a few cases. Cytochrome c nitrite reductases (NrfA) with similar properties were isolated from the soluble cell fractions of E. coli (), Vibrio fischeri [15,16] and Vibrio alginolyticus [148]. Putative nrfA genes were identified in several γ‐proteobacterial genomes (Table 3, see also ).…”

Section: Respiratory Nitrite Ammonification In Other Proteobacteriamentioning

confidence: 99%

Enzymology and bioenergetics of respiratory nitrite ammonification

Simon

2002

FEMS Microbiol Rev

348

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Nitrite is widely used by bacteria as an electron acceptor under anaerobic conditions. In respiratory nitrite ammonification an electrochemical proton potential across the membrane is generated by electron transport from a non-fermentable substrate like formate or H(2) to nitrite. The corresponding electron transport chain minimally comprises formate dehydrogenase or hydrogenase, a respiratory quinone and cytochrome c nitrite reductase. The catalytic subunit of the latter enzyme (NrfA) catalyzes nitrite reduction to ammonia without liberating intermediate products. This review focuses on recent progress that has been made in understanding the enzymology and bioenergetics of respiratory nitrite ammonification. High-resolution structures of NrfA proteins from different bacteria have been determined, and many nrf operons sequenced, leading to the prediction of electron transfer pathways from the quinone pool to NrfA. Furthermore, the coupled electron transport chain from formate to nitrite of Wolinella succinogenes has been reconstituted by incorporating the purified enzymes into liposomes. The NrfH protein of W. succinogenes, a tetraheme c-type cytochrome of the NapC/NirT family, forms a stable complex with NrfA in the membrane and serves in passing electrons from menaquinol to NrfA. Proteins similar to NrfH are predicted by open reading frames of several bacterial nrf gene clusters. In gamma-proteobacteria, however, NrfH is thought to be replaced by the nrfBCD gene products. The active site heme c group of NrfA proteins from different bacteria is covalently bound via the cysteine residues of a unique CXXCK motif. The lysine residue of this motif serves as an axial ligand to the heme iron thus replacing the conventional histidine residue. The attachment of the lysine-ligated heme group requires specialized proteins in W. succinogenes and Escherichia coli that are encoded by accessory nrf genes. The proteins predicted by these genes are unrelated in the two bacteria but similar to proteins of the respective conventional cytochrome c biogenesis systems.

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Section: Respiratory Nitrite Ammonification In Other Proteobacteriamentioning

confidence: 99%

Enzymology and bioenergetics of respiratory nitrite ammonification

Simon

2002

FEMS Microbiol Rev

348

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“…Nitrite was assayed colorimetrically [4], ammonia by enzymatic techniques [4]. Glucose and nitrate were determined enzymatically using testkits of Boehringer, Mannheim, F.R.G.…”

Section: Chemical Analysesmentioning

confidence: 99%

“…Depending on the end-products, two different pathways of dissimilatory nitrate reduction are distinguished: (i) denitrification, carried out by oxidative bacteria such as Pseudonomas sp., leads predominantly to gaseous products as nitrous oxide and molecular nitrogen [1]; (ii) alternatively, fermentative bacteria such as Klebsiella, Vibrio and Aeromonas, but also clostridia and Desulfovibrio sp. reduce nitrate to nitrite and subsequently to ammonia [2][3][4][5][6]. This process is called 'dissimilative nitrate reduction' or 'nitrate ammonification'.…”

Section: Introductionmentioning

confidence: 99%

Competition for nitrate between denitrifying Pseudomonas stutzeri and nitrate ammonifying enterobacteria

Rehr

1989

FEMS Microbiology Letters

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Competition for nitrate between nitrate ammonifying enterobacteria and a denitrifying pseudomonad was studied in electron acceptor‐limited chenostats. In pure cultures, using different carbon and energy sources, the C/N‐ratio needed for denitrification is far lower than that required for nitrate ammonification. In mixed cultures of Citrobacter freundii and Pseudomonas stutzeri, competing for nitrate with l‐lactate as electron donor, the nitrate ammonifying organism dominated at dilution rates of D ≤ 0.14 h−1. Competition for both nitrate and l‐lactate at a dilution rate of D = 0.05 h−1 always resulted in the coexistence of both species. Using glucose as additional carbon source, the final ratio of nitrate ammonifying and denitrifying organism depended on the C/N‐ratio as well as on the dilution rate. The results of the study are discussed with respect to field data.

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“…It was first isolated in 1981 from the sulfate‐reducing bacterium Desulfovibrio desulfuricans ATCC 27774 [3], when grown anaerobically in nitrate, instead of sulfate. Since then, a number of respiratory ammonia‐forming ccNiRs have been isolated from several nitrate‐grown bacteria as Escherichia coli K‐12 [4], Vibrio alginolyticus [5], Vibrio fisheri [6], Wolinella succinogenes [7] and Sulfurospirillum deleyianum [8]. Although not completely characterized, the iron‐reducing bacterium Geobacter metallireducens also exhibits cytochrome c nitrite reductase activity [9].…”

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The isolation and characterization of cytochrome c nitrite reductase subunits (NrfA and NrfH) from Desulfovibrio desulfuricans ATCC 27774

Almeida

Macieira

Gonçalves

et al. 2003

European Journal of Biochemistry

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The cytochrome c nitrite reductase is isolated from the membranes of the sulfate‐reducing bacterium Desulfovibrio desulfuricans ATCC 27774 as a heterooligomeric complex composed by two subunits (61 kDa and 19 kDa) containing c‐type hemes, encoded by the genes nrfA and nrfH, respectively. The extracted complex has in average a 2NrfA:1NrfH composition. The separation of ccNiR subunits from one another is accomplished by gel filtration chromatography in the presence of SDS. The amino‐acid sequence and biochemical subunits characterization show that NrfA contains five hemes and NrfH four hemes. These considerations enabled the revision of a vast amount of existing spectroscopic data on the NrfHA complex that was not originally well interpreted due to the lack of knowledge on the heme content and the oligomeric enzyme status. Based on EPR and Mössbauer parameters and their correlation to structural information recently obtained from X‐ray crystallography on the NrfA structure [Cunha, C.A., Macieira, S., Dias, J.M., Almeida, M.G., Gonçalves, L.M.L., Costa, C., Lampreia, J., Huber, R., Moura, J.J.G., Moura, I. & Romão, M. (2003) J. Biol. Chem. 278, 17455–17465], we propose the full assignment of midpoint reduction potentials values to the individual hemes. NrfA contains the high‐spin catalytic site (−80 mV) as well as a quite unusual high reduction potential (+150 mV)/low‐spin bis‐His coordinated heme, considered to be the site where electrons enter. In addition, the reassessment of the spectroscopic data allowed the first partial spectroscopic characterization of the NrfH subunit. The four NrfH hemes are all in a low‐spin state (S = 1/2). One of them has a gmax at 3.55, characteristic of bis‐histidinyl iron ligands in a noncoplanar arrangement, and has a positive reduction potential.

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Metabolic role and properties of nitrite reductase of nitrate-ammonifying marine Vibrio species

Cited by 7 publications

References 8 publications

Enzymology and bioenergetics of respiratory nitrite ammonification

Enzymology and bioenergetics of respiratory nitrite ammonification

Competition for nitrate between denitrifying Pseudomonas stutzeri and nitrate ammonifying enterobacteria

The isolation and characterization of cytochrome c nitrite reductase subunits (NrfA and NrfH) from Desulfovibrio desulfuricans ATCC 27774

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