1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Bradyrhizobium japonicum 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Salmonella enterica 2 ferricytochrome + nitrite - r 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Wolinella succinogenes 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Shewanella oneidensis 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Desulfovibrio desulfuricans 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Paracoccus pantotrophus 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Pseudomonas sp. 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Cupriavidus necator 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Cereibacter sphaeroides 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Shewanella gelidimarina 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Desulfitobacterium hafniense 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Anaeromyxobacter dehalogenans 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Campylobacter jejuni subsp. jejuni 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Methylotenera mobilis 2 ferricytochrome + nitrite - r 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Paracoccus denitrificans 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Escherichia coli 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Campylobacter jejuni subsp. jejuni ATCC 700819 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Cupriavidus necator H16 / ATCC 23440 / NCIB 10442 / S-10-1 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Salmonella enterica SL1344 AND CAL128 2 ferricytochrome + nitrite - r 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Pseudomonas sp. G-179 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Methylotenera mobilis JLW8 2 ferricytochrome + nitrite - r 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Cereibacter sphaeroides DSM 158 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 ferrocytochrome + 2 H+ + nitrate - Paracoccus pantotrophus GB17 2 ferricytochrome + nitrite - ? 440073 1.9.6.1 2 reduced methyl viologen + 2 H+ + nitrate artificial electron acceptor Methylotenera mobilis 2 oxidized methyl viologen + nitrite - r 440546 1.9.6.1 2 reduced methyl viologen + 2 H+ + nitrate artificial electron acceptor Methylotenera mobilis JLW8 2 oxidized methyl viologen + nitrite - r 440546 1.9.6.1 additional information the enzymes EC 1.7.99.4 and EC 1.9.6.1 are probably identical, in vivo cytochrome serves as electron donor in the electron transport chain to nitrate Aliivibrio fischeri ? - ? 89 1.9.6.1 additional information an insertion in the napA gene leads to a complete loss of enzyme activity but does not abolish the ability of Alcaligenes eutrophus to use nitrate as a nitrogen source or as an electron acceptor in anaerobic respiration. Nevertheless, the NAP-deficient mutant shows delayed growth after transition from aerobic to anaerobic respiration, suggesting a role for periplasmic nitrate reductase in the adaptation to anaerobic metabolism Cupriavidus necator ? - ? 89 1.9.6.1 additional information NapABC enzyme is responsible for nitrate dissimilation. Periplasmic nitrate reductase (NapABC enzyme) can function in anaerobic respiration but does not constitute a site for generating proton motive force. napF-lacZ is expressed preferentially at relatively low nitrate concentrations in continuous cultures. This finding support the hypothesis that NapABC enzyme may function in Escherichia coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme Escherichia coli K-12 ? - ? 89 1.9.6.1 additional information the nap operon encodes the only nitrate reductase in Campylobacter jejuni and that it is essential in mediating growth using nitrate as a terminal electron acceptor under oxygen-limited conditions Campylobacter jejuni ? - ? 89 1.9.6.1 additional information NapAB catalysed nitrate reduction driven by direct electron transfer from the electrode to NapAB, protein film voltammetry. Exploration of the nitrate reductase activity of purified NapAB as a function of electrochemical potential, substrate concentration and pH using protein film voltammetry. Nitrate reduction by NapAB occurs at potentials below approx. 0.1 V at pH 7. These are lower potentials than required for NarGH nitrate reduction. The potentials required for Nap nitrate reduction are also likely to require ubiquinol/ubiquinone ratios higher than are needed to activate the H+-pumping oxidases expressed during aerobic growth where Nap levels are maximal. Thus the operational potentials of Paracoccus pantotrophus NapAB are consistent with a productive role in redox balancing Paracoccus pantotrophus ? - ? 89 1.9.6.1 additional information the MoCo in Rhodobacter sphaeroides periplasmic nitrate reductase (NapAB) is subject to a slow, irreversible reductive activation Cereibacter sphaeroides ? - ? 89 1.9.6.1 additional information an insertion in the napA gene leads to a complete loss of enzyme activity but does not abolish the ability of Alcaligenes eutrophus to use nitrate as a nitrogen source or as an electron acceptor in anaerobic respiration. Nevertheless, the NAP-deficient mutant shows delayed growth after transition from aerobic to anaerobic respiration, suggesting a role for periplasmic nitrate reductase in the adaptation to anaerobic metabolism Cupriavidus necator H16 / ATCC 23440 / NCIB 10442 / S-10-1 ? - ? 89 1.9.6.1 additional information the MoCo in Rhodobacter sphaeroides periplasmic nitrate reductase (NapAB) is subject to a slow, irreversible reductive activation Cereibacter sphaeroides DSM 158 ? - ? 89 1.9.6.1 nitrate + ferrocytochrome - Pseudomonas aeruginosa nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome NapG and H, but not NapF, are essential for electron transfer from ubiquinol to NapAB. NapC is essential for electron transfer from both ubiquinol and menaquinol to NapAB. It is proposed that NapG and H form an energy conserving quinol dehydrogenase functioning as either components of a proton pump or in a Q cycle, as electrons are transferred from ubiquinol to the membrane-bound cytochrome NapC Escherichia coli K-12 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome periplasmic nitrate reductase is expressed under nitrate-limiting conditions. NapG and NapH form a quinol dehydrogenase that couples electron transfer from the high midpoint redox potential ubiquinone-ubiquinol couple via cytochrome NapC and NapB to NapA Escherichia coli K-12 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the periplasmic cytochrome c-linked nitrate reductase is encoded by the napFDAGHBC operon. The napF operon apparently encodes a low-substrate-induced reductase that is maximally expressed only at low levels of nitrate. Expression is suppressed under high-nitrate conditions. In contrast, the narGHJI operon is only weakly expressed at low nitrate levels but is maximally expressed when nitrate is elevated. The narGHJI operon is therefore a high-substrate-induced operon that somehow provides a second and distinct role in nitrate metabolism by the cell. Nitrite, the end product of each enzyme, has only a minor effect on the expression of either operon. Finally, nitrate, but not nitrite, is essential for repression of napF gene expression. These studies reveal that nitrate rather than nitrite is the primary signal that controls the expression of these two nitrate reductase operons in a differential and complementary fashion Escherichia coli nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome NapG and NapH form a quinol dehydrogenase that couples electron transfer from the high midpoint redox potential ubiquinone–ubiquinol couple via cytochrome NapC and NapB to NapA Escherichia coli K-12 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the membrane-bound cytochrome NapC is essential for electron transfer from both ubiquinol and menaquinol to NapAB Escherichia coli K-12 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sp. nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella putrefaciens nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella oneidensis nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella frigidimarina nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella halifaxensis nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella loihica nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella pealeana nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella piezotolerans nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sediminis nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella woodyi nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella denitrificans nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella amazonensis nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella baltica nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella piezotolerans WP3 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella putrefaciens CN-32 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella baltica OS195 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sp. ANA-3 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella baltica OS223 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sp. W3-18-1 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella denitrificans OS217 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella baltica OS155 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella loihica PV-4 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sp. MR-4 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella oneidensis MR-1 / ATCC 700550 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella baltica OS185 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella sp. MR-7 nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + ferrocytochrome the reduction of nitrate catalysed by NAP takes place in the 90 kDa NapA subunit Shewanella amazonensis SB2B nitrite + ferricytochrome + H2O - ? 402794 1.9.6.1 nitrate + reduced acceptor reduced benzyl viologen as electron donor Aliivibrio fischeri nitrite + acceptor - ? 260661 1.9.6.1 nitrate + reduced acceptor reduced methyl viologen as electron donor Aliivibrio fischeri nitrite + acceptor - ? 260661 1.9.6.1 nitrate + reduced acceptor the enzymes EC 1.7.99.4 and EC 1.9.6.1 are probably identical, in vivo cytochrome serves as electron donor in the electron transport chain to nitrate Aliivibrio fischeri nitrite + acceptor - ? 260661 1.9.6.1 nitrate + reduced acceptor electron transport chain in vivo: Fe3 + via specific cytochrome-nitrate reductase to NO3- Aliivibrio fischeri nitrite + acceptor - ? 260661 1.9.6.1 nitrate + reduced acceptor - Desulfovibrio desulfuricans nitrite + oxidized acceptor - ? 402797 1.9.6.1 nitrate + reduced benzyl viologen - Paracoccus pantotrophus nitrite + oxidized benzyl viologen - ? 406130 1.9.6.1 nitrate + reduced benzyl viologen - Cupriavidus necator nitrite + oxidized benzyl viologen + H2O - ? 406131 1.9.6.1 nitrate + reduced benzyl viologen - Escherichia coli K-12 nitrite + oxidized benzyl viologen + H2O - ? 406131 1.9.6.1 nitrate + reduced benzyl viologen - Cereibacter sphaeroides f. sp. denitrificans nitrite + oxidized benzyl viologen + H2O - ? 406131 1.9.6.1 nitrate + reduced benzyl viologen - Achromobacter sp. MMT nitrite + oxidized benzyl viologen + H2O - ? 406131 1.9.6.1 nitrate + reduced benzyl viologen - Cupriavidus necator H16 / ATCC 23440 / NCIB 10442 / S-10-1 nitrite + oxidized benzyl viologen + H2O - ? 406131 1.9.6.1 nitrate + reduced methyl viologen - Paracoccus pantotrophus nitrite + oxidized methyl viologen - ? 289497 1.9.6.1 nitrate + reduced methyl viologen - Paracoccus denitrificans nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrate + reduced methyl viologen - Escherichia coli K-12 nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrate + reduced methyl viologen - Paracoccus pantotrophus nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrate + reduced methyl viologen - Campylobacter jejuni nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrate + reduced methyl viologen very high substrate specificity. The enzyme does not reduce any other oxocompound (chlorate, bromate, iodate, nitrite, molybdate, sulphate, thiosulphate, tetrathionate, selenate, dimethyl sulphoxide, trimethylamine-A-oxide, borate and arsenate) Paracoccus pantotrophus nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrate + reduced methyl viologen - Campylobacter jejuni RM1221 nitrite + oxidized methyl viologen + H2O - ? 406132 1.9.6.1 nitrite + methyl viologen - Pseudomonas aeruginosa nitrate + oxidized methyl viologen - ? 415045