Information on EC 1.7.99.4 - nitrate reductase

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The expected taxonomic range for this enzyme is: Eukaryota, Bacteria, Archaea

EC NUMBER
COMMENTARY hide
1.7.99.4
-
RECOMMENDED NAME
GeneOntology No.
nitrate reductase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
nitrite + acceptor = nitrate + reduced acceptor
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oxidation
redox reaction
-
-
-
-
reduction
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Microbial metabolism in diverse environments
-
-
nitrate assimilation
-
-
Nitrogen metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
nitrite:acceptor oxidoreductase
The Pseudomonas enzyme is a cytochrome, but the enzyme from Micrococcus halodenitrificans is an iron protein containing molybdenum. Reduced benzyl viologen and other dyes bring about the reduction of nitrate.
CAS REGISTRY NUMBER
COMMENTARY hide
37256-45-4
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
cultivar Smooth Cayenne
UniProt
Manually annotated by BRENDA team
strain Sp245, NAP is expressed under oxic and anoxic conditions
-
-
Manually annotated by BRENDA team
strain Sp245, NAP is expressed under oxic and anoxic conditions
-
-
Manually annotated by BRENDA team
strain S244
-
-
Manually annotated by BRENDA team
strain S244
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
USDA110
-
-
Manually annotated by BRENDA team
strain ATCC 27774
-
-
Manually annotated by BRENDA team
strain IFO 12935
-
-
Manually annotated by BRENDA team
strain IFO 12935
-
-
Manually annotated by BRENDA team
strain A1004a, 5-aminolaevulinic acid auxotroph
-
-
Manually annotated by BRENDA team
strain EMG 29
-
-
Manually annotated by BRENDA team
strain EMG-2
-
-
Manually annotated by BRENDA team
strain RK7
-
-
Manually annotated by BRENDA team
strain X5119
-
-
Manually annotated by BRENDA team
Fusarium oxysporum 11dn1
-
-
Manually annotated by BRENDA team
NCA strain 2184, identical with ATCC 12016
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
extreme halophile
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
I3R9M9: alpha-subunit (narG), I3R9M8: beta subunit (narH)
I3R9M9 and I3R9M8
SwissProt
Manually annotated by BRENDA team
halophilic archaeon
-
-
Manually annotated by BRENDA team
strain ATCC 13511, moderate halophile, nitrate reductase A
-
-
Manually annotated by BRENDA team
strain AGJ1-3
-
-
Manually annotated by BRENDA team
strain AGJ1-3
-
-
Manually annotated by BRENDA team
strain MS-1
Swissprot
Manually annotated by BRENDA team
strain MS-1
Swissprot
Manually annotated by BRENDA team
strain 617
-
-
Manually annotated by BRENDA team
strain NCIB 8944
-
-
Manually annotated by BRENDA team
strain LMD82.5, expression of two catalytically distinct forms: a membrane-bound form under anaerobic growth conditions and a periplasmic form mainly under aerobic growth conditions
-
-
Manually annotated by BRENDA team
strain M-6
-
-
Manually annotated by BRENDA team
strain ATCC 13867
-
-
Manually annotated by BRENDA team
strain YT101
-
-
Manually annotated by BRENDA team
strain DSM158, in vitro enzyme activity after different growth conditions
-
-
Manually annotated by BRENDA team
strain RF-1, diazotrophically growing cells
-
-
Manually annotated by BRENDA team
strain RF-1, diazotrophically growing cells
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
physiological function
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
chlorate + reduced acceptor
?
show the reaction diagram
chlorate + reduced acceptor
chlorite + acceptor
show the reaction diagram
dithionite + methyl viologen
?
show the reaction diagram
nitrate + reduced acceptor
?
show the reaction diagram
nitrate + reduced acceptor
nitrite + acceptor
show the reaction diagram
nitrate + reduced acceptor
nitrite + acceptor + H2O
show the reaction diagram
-
Wolinella succinogenes transfers electrons from formate via the menaquinone pool to NapA independently of a membrane-bound c-type cytochrome of the NapC family. The napB and napD gene products are essential for nitrate respiration. NapD is required for the production of mature NapA. NapF or NapL function in NapA assembly and/or export
-
-
?
nitrate + reduced acceptor
nitrite + oxidized acceptor
show the reaction diagram
nitrate + reduced benzyl viologen
nitrite + benzyl viologen
show the reaction diagram
nitrate + reduced benzyl viologen
nitrite + oxidized benzyl viologen
show the reaction diagram
-
-
-
-
?
nitrate + reduced benzyl viologen
nitrite + oxidized benzyl viologen + H2O
show the reaction diagram
nitrate + reduced methyl viologen
nitrite + methyl viologen
show the reaction diagram
nitrate + reduced methyl viologen
nitrite + oxidized methyl viologen
show the reaction diagram
nitrate + reduced methyl viologen
nitrite + oxidized methyl viologen + H2O
show the reaction diagram
-
the purified enzyme does not react with duroquinol or NADH. It may be that the purified enzyme has lost some of the components that mediate the electron transport from the physiological reductant to the catalytic 63000 Da polypeptide during the purification process
-
-
?
nitrate + reduced methylviologen
nitrite + oxidized methyl viologen + H2O
show the reaction diagram
nitrite + acceptor
nitrate + reduced acceptor
show the reaction diagram
reduced methyl viologen + chlorate
methyl viologen + chlorite
show the reaction diagram
reduced methyl viologen + nitrate
methyl viologen + nitrite
show the reaction diagram
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
nitrate + reduced acceptor
nitrite + acceptor
show the reaction diagram
nitrate + reduced acceptor
nitrite + acceptor + H2O
show the reaction diagram
-
Wolinella succinogenes transfers electrons from formate via the menaquinone pool to NapA independently of a membrane-bound c-type cytochrome of the NapC family. The napB and napD gene products are essential for nitrate respiration. NapD is required for the production of mature NapA. NapF or NapL function in NapA assembly and/or export
-
-
?
nitrate + reduced acceptor
nitrite + oxidized acceptor
show the reaction diagram
-
a model of the electron transport chain of nitrate respiration is proposed in which one or more of the napF, G, H and L gene products mediate electron transport from menaquinol to the periplasmic NapAB complex
-
-
?
nitrite + acceptor
nitrate + reduced acceptor
show the reaction diagram
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
Bactopterin
-
common cofactor of eubacterial molybdoenzymes
cytochrome b
FAD
-
assimilatory nitrate reductases
heme b
heme c
iron-sulfur centre
molybdenum bis-molybdopterin guanine dinucleotide
-
one bis-MGD cofactor in a single polypeptide chain of 723 amino acids, extends across the interior of the molecule interacting with residues from all 4 domains, catalytic molybdenum site is coordinated to two MGD cofactors, Cys140 and a water/hydroxo ligand
molybdenum cofactor
molybdo-(bismolybdopterin)guanine dinucleotide
-
Mo-bis-MGD, NapA of the periplasmic nitrate reductase, assimilatory nitrate reductases
molybdo-bis(pyranopterin guanine dinucleotide)
-
molybdopterin guanine dinucleotide
NAD(P)H
[4Fe-4S]-center
-
additional information
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
iron-sulfur centre
KCl
-
maximum activity occurrs in the absence of NaCl and decreases with increasing concentrations of NaCl so that the activity is 46% of maximum when the enzyme is assayed in the presence of 4 M NaCl. Replacing NaCl with KCl does not significantly change the response
Molybdenum
Tungsten
-
0.06 mol tungsten per mol of enzyme complex
WO42-
-
enzyme purified from cells grown with 4.5 M WO42- contains W as the metal cofactor. W is coordinated by a bis-molybdopterin guanine dinucleotide cofactor
[3Fe-4S] center
-
the amount of iron determined was consistent with the presence of one [3Fe-4S] center and four [4Fe-4S] centers
[4Fe-4S] center
-
the amount of iron determined was consistent with the presence of one [3Fe-4S] center and four [4Fe-4S] centers
additional information
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2-n-heptyl-4-hydroxyquinoline N-oxide
-
only effective as inhibitor with the three-subunit enzyme and duroquinol as substrate
ammonium sulfate
-
ammonium sulfate and other ammonium salts inhibit
bathophenanthroline
-
uncompetitive inhibition
bathophenanthroline-sulfonate
-
uncompetitive inhibition
bromate
-
competitive inhibitor, 1 mM, 50% inhibition
Chlorate
cyanide
Dithiol
-
0.1 mM, 95% inhibition
Dithionite
-
1 mM, 24% loss of activity
dithiothreitol
EDTA
-
1 mM, 22% loss of activity
ferricyanide
-
at pH 10.5 the as prepared enzyme is inactivated
IO3-
-
1 mM, 40% inhibition
KClO4
-
1 mM, 33% inhibition
Mepacrine
-
1 mM, 40% inhibition
metronidazole
-
2 mM metronidazole inhibits nitrate reduction by 6.7% in the whole-cell lysate
NaCN
-
0.04 mM, complete inhibition
NaN3
-
0.04 mM, 59% inhibition
NH4HCO3
-
3.87 mM, complete inhibition
Nitrofurantoin
-
0.3 mM nitrofurantoin inhibits nitrate reduction by 19.5% in the whole-cell lysate
o-phenanthroline
-
3 mM, 25% inhibition
oxygen
p-chloromercuribenzoate
Sodium azide
-
-
Sodium cyanide
-
-
Sulfide
Thiocyanate
additional information
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
deoxycholate
-
activates
ferricyanide
-
enzyme as prepared is slowly activated at pH 7.2 over 250% of the original activity, dependent on ferricyanide concentration, little activation at pH 9.5
isopentenyladenine
nitrate reductase expression and activity in both roots and shoots of pineapple are significantly enhanced by isopentenyladenine
isopentenyladenine riboside
nitrate reductase expression and activity in both roots and shoots of pineapple are significantly enhanced by isopentenyladenine riboside
K3Fe(CN)6
-
the enzyme, inactive in vivo, may be reactivated in vitro by oxidation with K3Fe(CN)6
KNO3
-
10 mM, up to 4fold activation
nitrate
nitrite
-
the activity of the 125000 Da complex increases strikingly from 0.1 mM to 1 mM nitrite added, however, within the higher range of available nitrite, the intensity of this form decreases dramatically, whereas the activity of the 140000 Da band starts to grow in strength
p-chloromercuribenzoate
-
enhances enzyme activity at 0.1 mM and lower concentrations
zeatin
nitrate reductase expression and activity in both roots and shoots of pineapple are significantly enhanced by zeatin
zeatin riboside
nitrate reductase expression and activity in both roots and shoots of pineapple are significantly enhanced by zeatin riboside
additional information
-
4fold activation by heating to 75C for 75 min
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0022 - 0.0029
benzyl viologen
0.138 - 5
Chlorate
0.25
methyl viologen
-
-
0.0032 - 5
nitrate
0.0002 - 1.6
reduced benzyl viologen
0.0028 - 1.5
reduced methyl viologen
additional information
additional information
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
1350
Chlorate
Pyrobaculum aerophilum
-
at 75C
2.5 - 1162
nitrate
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.00013 - 0.55
azide
0.5 - 0.8
bathophenanthroline
1.3 - 2.4
bathophenanthroline-sulfonate
0.8 - 1.7
Chlorate
0.044 - 0.5
cyanide
0.16 - 0.28
Sulfide
1.4
Thiocyanate
-
nitrate as substrate
IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0182 - 0.036
azide
0.0134 - 0.11
cyanide
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.0003
-
nitrate, 10 mM NH4+, NADPH, aerobic
0.0057
-
nitrate, medium without nitrogen, NADPH, aerobic
0.0129
-
nitrate, 10 mM NO3-, NADPH, aerobic
0.0186
-
nitrate, 10 mM NH4+, methyl viologen, aerobic; nitrate, 10 mM NH4+, NADPH, anaerobic
0.02 - 0.04
-
rate of physiological reduction, lower than that obtained with reduced benzyl viologen
0.02
-
nitrate, medium without nitrogen, methyl viologen, aerobic
0.066
-
nitrate, medium without nitrogen, NADPH, anaerobic
0.0705
-
nitrate, 10 mM NO3-, methyl viologen, aerobic; nitrate, 10 mM NO3-, NADPH, anaerobic
0.0754
-
nitrate, 10 mM NH4+, methyl viologen, anaerobic
0.2659
-
nitrate, medium without nitrogen, methyl viologen, anaerobic
0.342
-
methyl viologen as electron donor, aerobic growth conditions, assay in intact cells
0.39
-
nitrate/nitrite reductase complex
0.423
-
nitrate, 10 mM NO3-, methyl viologen, anaerobic
0.523
-
benzyl viologen as electron donor, aerobic growth conditions, assay in intact cells
1.407
-
benzyl viologen as electron donor, anaerobic growth conditions, assay in intact cells
2.018
-
methyl viologen as electron donor, anaerobic growth conditions, assay in intact cells
2.157
-
methyl viologen as electron donor, microaerobic growth conditions, assay in intact cells
2.264
-
benzyl viologen as electron donor, microaerobic growth conditions, assay in intact cells
2.63
-
enzyme in cell-free extract
24.5
-
nitrate reductase I
35
P85098 and P85097
after 76fold purification
39.1
-
nitrate reductase II
62
-
37C, pH 7.2
160
-
at 30C, both enzyme forms, reduced benzyl viologen as reductant
229
-
at 30C
326
-
nitrate as substrate, at 75C
378
-
chlorate as substrate, at 75C
2530
-
pH 7.4, 30C
additional information
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.3
-
nitrate as substrate
6.4
-
chlorate as substrate
6.8
-
broad pH-optimum from pH 5.8 to pH 7.1 with maximum at pH 6.8
7.1
-
nitrate as substrate
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 8
-
the activities at pH 6.0 and pH 8.0 are 83% and 81% of the activity at pH 7.2
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
23
-
assay at
32
activity assay; activity assay; activity assay; activity assay; activity assay
56
-
presence of 0.5 mM MgCl2
70
-
at 3.4 M NaCl
73
-
presence of 2 M KCl
85
-
presence of 4.27 M NaCl
95
-
highest activity at or above
additional information
-
temperature optimum is a function of both: the concentration and the specific cation present, increasing NaCl and KCl concentrations result in an increase in the maximal activity at higher temperatures
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
70 - 80
-
maximal activity
additional information
-
-
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7.1
-
calculated
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
additional information
-
NapG and NapH proteins form a membrane-bound protein complex that is likely to catalyse menaquinol oxidation and electron transport to the periplasmic NapAB nitrate reductase complex
-
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
UNIPROT
Cupriavidus necator (strain ATCC 17699 / H16 / DSM 428 / Stanier 337)
Cupriavidus necator (strain ATCC 17699 / H16 / DSM 428 / Stanier 337)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Rhodobacter sphaeroides (strain ATCC 17023 / 2.4.1 / NCIB 8253 / DSM 158)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
23000
-
enzyme form predominating in the membrane fraction, SDS-PAGE
26000
-
gel filtration
28690
calculated, NarJ
46060
calculated, NarK
59000
P85098 and P85097
two bands of 65 kDa and 59 kDa are obtained as beta-subunit after purification, SDS-PAGE
60840
calculated, NarH
65000
P85098 and P85097
two bands of 65 kDa and 59 kDa are obtained as beta-subunit after purification, SDS-PAGE
125000
-
enzyme form with remarkably increased activity, SDS-PAGE
130000
-
determined by SDS-PAGE
137000
P85098 and P85097
purified homogenous alpha subunit, non-denaturing PAGE
140000
-
active enzyme form, SDS-PAGE
141400
calculated, NarG
165000
-
mean value, real value between 155000 Da and 175000 Da, PAGE
176000
180000 - 220000
P85098 and P85097
purified native enzyme, gel filtration
180000
190000
-
in the nitrate-fed cells, the 190000 Da form is the most abundant, SDS-PAGE
196000
-
always present in a monomeric form, PAGE
200000
208000
-
gel filtration