Inhibitors | Comment | Organism | Structure |
---|---|---|---|
azide | 1 mM, 90% inhibition | Haloferax alexandrinus | |
cyanide | 1 mM, 98% inhibition | Haloferax alexandrinus | |
EDTA | 1 mM, 52% inhibition | Haloferax alexandrinus | |
sulfite | 1 mM, 30% inhibition | Haloferax alexandrinus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.045 | - |
nitrate | 120 mM Na2CO3 pH 9, 1 M NaCl, 4 mM methyl viologen, 35 mM KNO3, 17 mM Na2S2O4 (freshly prepared in 0.1 M NaHCO3) and 0.7 mU of enzyme preparations. The samples are incubated for 20 min at 60°C | Haloferax alexandrinus | |
0.0646 | - |
reduced methyl viologen | 120 mM Na2CO3 pH 9, 1 M NaCl, 4 mM methyl viologen, 35 mM KNO3, 17 mM Na2S2O4 (freshly prepared in 0.1 M NaHCO3) and 0.7 mU of enzyme preparations. The samples are incubated for 20 min at 60°C | Haloferax alexandrinus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
iron-sulfur centre | - |
Haloferax alexandrinus | |
KCl | up to 2 M, the highest the salt concentration, the highest the activity value. Activity is significantly higher in the presence of KCl than in the presence of NaCl | Haloferax alexandrinus | |
NaCl | up to 2 M, the highest the salt concentration, the highest the activity value. Activity is significantly higher in the presence of KCl than in the presence of NaCl | Haloferax alexandrinus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
72000 | - |
- |
Haloferax alexandrinus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
nitrate + 2 reduced ferredoxin + 2 H+ | Haloferax alexandrinus | the enzyme is involved in aerobic assimilatory nitrate reduction. The enzyme enables Haloferax alexandrinus to use nitrate as sole nitrogen source for growth under aerobic conditions. Haloferax alexandrinus may induce denitrification under anaerobic or microaerobic conditions using nitrate as electron acceptor | nitrite + H2O + 2 oxidized ferredoxin | - |
? | |
nitrate + 2 reduced ferredoxin + 2 H+ | Haloferax alexandrinus JCM 10717 | the enzyme is involved in aerobic assimilatory nitrate reduction. The enzyme enables Haloferax alexandrinus to use nitrate as sole nitrogen source for growth under aerobic conditions. Haloferax alexandrinus may induce denitrification under anaerobic or microaerobic conditions using nitrate as electron acceptor | nitrite + H2O + 2 oxidized ferredoxin | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Haloferax alexandrinus | M0HXK1 | - |
- |
Haloferax alexandrinus JCM 10717 | M0HXK1 | - |
- |
Purification (Comment) | Organism |
---|---|
- |
Haloferax alexandrinus |
Storage Stability | Organism |
---|---|
4°C, activity decreases about 40% in 1 week when the crude extract is stored. At temperatures higher than 4°C, the activity depletion in the crude extract is 6080% | Haloferax alexandrinus |
4°C, the activity of the pure sample is stable for 23 weeks | Haloferax alexandrinus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
nitrate + 2 reduced ferredoxin + 2 H+ | the enzyme is involved in aerobic assimilatory nitrate reduction. The enzyme enables Haloferax alexandrinus to use nitrate as sole nitrogen source for growth under aerobic conditions. Haloferax alexandrinus may induce denitrification under anaerobic or microaerobic conditions using nitrate as electron acceptor | Haloferax alexandrinus | nitrite + H2O + 2 oxidized ferredoxin | - |
? | |
nitrate + 2 reduced ferredoxin + 2 H+ | the enzyme is involved in aerobic assimilatory nitrate reduction. The enzyme enables Haloferax alexandrinus to use nitrate as sole nitrogen source for growth under aerobic conditions. Haloferax alexandrinus may induce denitrification under anaerobic or microaerobic conditions using nitrate as electron acceptor | Haloferax alexandrinus JCM 10717 | nitrite + H2O + 2 oxidized ferredoxin | - |
? | |
nitrate + reduced methyl viologen | reduced methyl viologen is the best electron donor. No activity with either NADH (1 mM) or NADPH (1 mM) (in the presence or absence of dithionite within the reaction mixture). Dithionite is not able to reduce nitrate in the absence of reduced methyl viologen | Haloferax alexandrinus | nitrite + H2O + oxidized methyl viologen | - |
? | |
nitrate + reduced methyl viologen | reduced methyl viologen is the best electron donor. No activity with either NADH (1 mM) or NADPH (1 mM) (in the presence or absence of dithionite within the reaction mixture). Dithionite is not able to reduce nitrate in the absence of reduced methyl viologen | Haloferax alexandrinus JCM 10717 | nitrite + H2O + oxidized methyl viologen | - |
? |
Subunits | Comment | Organism |
---|---|---|
monomer | 1 * 72000, SDS-PAGE, taking into account that molecular masses of halophilic proteins are overestimated in SDS-PAGE (around 1317%) a molecular mass of around 70000 would be expected | Haloferax alexandrinus |
monomer | 1 * 76050, calculated from nucleotide sequence | Haloferax alexandrinus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
50 | - |
the enzyme shows a remarkable thermophilicity and works well up to 50°C in the presence of high salt concentrations | Haloferax alexandrinus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
9.5 | - |
- |
Haloferax alexandrinus |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
5 | 11 | pH 5.0: about 50% of maximal activity, pH 11.0: about 80% of maximal activity | Haloferax alexandrinus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
iron-sulfur centre | - |
Haloferax alexandrinus |
Organism | Comment | pI Value Maximum | pI Value |
---|---|---|---|
Haloferax alexandrinus | calculated from amino acid sequence | - |
4.52 |
Organism | Comment | Expression |
---|---|---|
Haloferax alexandrinus | activity is detected between 72 and 168 h of incubation, and it reaches the maximum value when the absorbance of the culture is around 0.47 (at 600 nm). This maximum activity value is observed shortly after the beginning of the exponential phase of growth, and in that moment, high nitrite concentration within the media is quantified (up to 18.8 mM). This growth phase is characterised by oxygen depletion (culture medium is initially aerobic, but it becomes microaerobic as soon as the biomass increases shortly before the stationary phase of growth) | up |