Formate‐Nitrite Reduction in <i>Escherichia coli K12</i>

Abou-Jaoudé, A.; Chippaux, Marc; Pascal, Marie-Claire

doi:10.1111/j.1432-1033.1979.tb12966.x

Cited by 51 publications

(19 citation statements)

References 12 publications

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“…We found that the inhibition profile of the nitrite reductase activity of the purified cytochrome c552 with several inhibitors coincided with that of the cellular formate/ nitrite reductase [33]. Cytochrome c552 is probably the inhibition site of cyanide and cupric ion in the system.…”

Section: Discussionmentioning

confidence: 63%

Purification of a hexaheme cytochrome C552 from Escherichia coli K 12 and its properties as a nitrite reductase

Kajie

Anraku

1986

Eur J Biochem

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Anaerobic cytochrome c 5 5 2 was purified to electrophoretic homogeneity by ion-exchange chromatography and gel filtration from a mutant of Escherichiu coli K 12 that synthesizes an increased amount of this pigment. Several molecular and enzymatic properties of the cytochrome were investigated. Its relative molecular mass was determined to be 69000 by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. It was found to be an acidic protein that existed in the monomeric form in the native state. From its heme and iron contents, it was concluded to be a hexaheme protein containing six moles of heme c/mole protein. The amino-acid composition and other properties of the purified cytochrome c 5 5 2 indicated its similarity to Desulfbvibrio desulfuricans hexaheme cytochrome. The cytochrome ~5 5 2 showed nitrite and hydroxylamine reductase activities with benzyl viologen a s an artificial electron donor. It catalyzed the reduction of nitrite to ammonia in a six-electron transfer. FMN and FAD also served as electron donors for the nitrite reduction. The apparent Michaelis constants for nitrite and hydroxylamine were 110 pM and 18 mM, respectively. The nitrite reductase activity of the cytochrome cSs2 was inhibited effectively by cupric ion and cyanide.A soluble c-type cytochrome, cytochrome ( ' 5 5 2 is synthesized in Escherichiu coli and some other Enterobacteriacede when they are grown anaerobically [I, 21. Biosynthesis of this cytochrome is repressed by molecular oxygen and stimulated anaerobically by the presence of nitrate or nitrite in the medium [ 3 , 41. In E. coli K12, this synthesis is under the control of an activator protein encoded by the j n r gene, which is necessary for the induced synthesis of a number of components in the anaerobic respiratory systems, including nitrate reductase, nitrite reductase, fumarate reductase, and hydrogenase reported that reduced cytochrome c S s 2 from E. coli Yamaguchi is rapidly reoxidized by addition of nitrite. They found that cytochrome ~5 5 2 is located in the periplasinic space [8] and concluded that its in vivo function is reduction of toxic nitrite produced by nitrate respiration to ammonia at the cell surface 191. However, the protein-chemical properties of the cytochrome as a nitrite reductase have not been studied extensively.Abou-Jaoudt et al. [lo] proposed the possible involvement of cytochrome ~5 5 2 in the formate/nitrite reductase system in whole cells of E. coli K12. Energy conservation during formate-dependent reduction of nitrite by E. coli was demonstrated [I 1, 121. Moreover, from reconstitution experiments, Liu et al. 1131 suggested the role of cytochrome ~5 5 2 as a terminal nitrite reductase in NADH-dependent nitrite reduction. However, the exact physiological function ofcytochrome has not yet been elucidated.

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Section: Discussionmentioning

confidence: 63%

Purification of a hexaheme cytochrome C552 from Escherichia coli K 12 and its properties as a nitrite reductase

Kajie

Anraku

1986

Eur J Biochem

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“…When nitrate concentration dropped below our limit of detection (0.5 mM) at 8.5 h, the current remained at ~ −0.5 mA, most likely due to the commencement of nitrite reduction. E. coli is known to preferentially reduce nitrate with the stoichiometry 1MKH 2 + 1NO 3 − → 1MK + 1NO 2 − , followed by a switch to nitrite reduction (Lin and Iuchi, 1991), with the stoichiometry 3MKH 2 + 1NO 2 − → 3MK + 1NH 4 (Abou-Jaoude et al, 1979). …”

Section: Resultsmentioning

confidence: 99%

The mechanism of neutral red-mediated microbial electrosynthesis in Escherichia coli: menaquinone reduction

Harrington

Tran

Mohamed

et al. 2015

Bioresource Technology

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The aim of this work was to elucidate the mechanism of mediated microbial electrosynthesis via neutral red from an electrode to fermenting Escherichia coli cultures in a bioelectrochemical system. Chemical reduction of NAD+ by reduced neutral red did not occur as predicted. Instead, neutral red was shown to reduce the menaquinone pool in the inner bacterial membrane. The reduced menaquinone pool altered fermentative metabolite production via the arcB redoxsensing cascade in the absence of terminal electron acceptors. When the acceptors DMSO, fumarate, or nitrate were provided, as many as 19% of the electrons trapped in the reduced acceptors were derived from the electrode. These results demonstrate the mechanism of neutral red-mediated microbial electrosynthesis during fermentation as well as how neutral red enables microbial electrosynthesis of reduced terminal electron acceptors.

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“…Nitrite ammonification is widespread in γ‐proteobacteria [147]. However, the corresponding enzymes or the capability of respiratory nitrite ammonification were characterized in only a few cases.…”

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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Formate‐Nitrite Reduction in Escherichia coli K12

Cited by 51 publications

References 12 publications

Purification of a hexaheme cytochrome C552 from Escherichia coli K 12 and its properties as a nitrite reductase

Purification of a hexaheme cytochrome C552 from Escherichia coli K 12 and its properties as a nitrite reductase

The mechanism of neutral red-mediated microbial electrosynthesis in Escherichia coli: menaquinone reduction

Enzymology and bioenergetics of respiratory nitrite ammonification

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