BRENDA - Enzyme Database show

Effects on substrate reduction of substitution of histidine-195 by glutamine in the alpha-subunit of the MoFe protein of Azotobacter vinelandii nitrogenase

Dilworth, M.J.; Fisher, K.; Kim, C.H.; Newton, W.E.; Biochemistry 37, 17495-17505 (1998)

Data extracted from this reference:

Engineering
EC Number
Amino acid exchange
Commentary
Organism
1.18.6.1
H195Q
below 2% N2 reducing activity remaining compared to wild-type due to less effective N2 binding
Azotobacter vinelandii
Inhibitors
EC Number
Inhibitors
Commentary
Organism
Structure
1.18.6.1
N2
inhibits C2H2 reduction of mutant H195Q; maximal inhibition of H2 production at Fe protein to MoFe protein ration 2.5
Azotobacter vinelandii
1.18.6.1
N3-
inhibits H2 production competitively and reversibly
Azotobacter vinelandii
KM Value [mM]
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.18.6.1
additional information
-
additional information
-
Azotobacter vinelandii
Metals/Ions
EC Number
Metals/Ions
Commentary
Organism
Structure
1.18.6.1
Mg2+
Mg2+ required for MgATP complex
Azotobacter vinelandii
Natural Substrates/ Products (Substrates)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
Azotobacter vinelandii
-
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
-
?
Organism
EC Number
Organism
Primary Accession No. (UniProt)
Commentary
Textmining
1.18.6.1
Azotobacter vinelandii
-
-
-
Purification (Commentary)
EC Number
Commentary
Organism
1.18.6.1
wild-type and mutant H195Q
Azotobacter vinelandii
Reaction
EC Number
Reaction
Commentary
Organism
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O = 8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
enzyme is composed of 2 metalloproteins: component I MoFe protein and component II Fe protein
Azotobacter vinelandii
Specific Activity [micromol/min/mg]
EC Number
Specific Activity Minimum [mol/min/mg]
Specific Activity Maximum [mol/min/mg]
Commentary
Organism
1.18.6.1
additional information
-
assay in anaerobic atmosphere required
Azotobacter vinelandii
1.18.6.1
0.024
-
purified mutant H195Q enzyme, anaerobic atmosphere
Azotobacter vinelandii
1.18.6.1
0.7
-
purified enzyme, anaerobic atmosphere
Azotobacter vinelandii
Substrates and Products (Substrate)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
-
440184
Azotobacter vinelandii
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
-
-
?
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
-
440184
Azotobacter vinelandii
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
440184
Azotobacter vinelandii
?
1.18.6.1
reduced ferredoxin + H+ + ATP
-
440184
Azotobacter vinelandii
oxidized ferredoxin + H2 + ADP + phosphate
-
440184
Azotobacter vinelandii
?
1.18.6.1
reduced ferredoxin + H+ + N3- + ATP
mutant H195Q shows only about 7.5% activity compared to wild-type
440184
Azotobacter vinelandii
oxidized ferredoxin + NH3 + N2 + ADP + phosphate
-
440184
Azotobacter vinelandii
?
Temperature Optimum [C]
EC Number
Temperature Optimum [C]
Temperature Optimum Maximum [C]
Commentary
Organism
1.18.6.1
additional information
-
-
Azotobacter vinelandii
Temperature Range [C]
EC Number
Temperature Minimum [C]
Temperature Maximum [C]
Commentary
Organism
1.18.6.1
13
45
-
Azotobacter vinelandii
Ki Value [mM]
EC Number
Ki Value [mM]
Ki Value maximum [mM]
Inhibitor
Commentary
Organism
Structure
1.18.6.1
additional information
-
additional information
-
Azotobacter vinelandii
Engineering (protein specific)
EC Number
Amino acid exchange
Commentary
Organism
1.18.6.1
H195Q
below 2% N2 reducing activity remaining compared to wild-type due to less effective N2 binding
Azotobacter vinelandii
Inhibitors (protein specific)
EC Number
Inhibitors
Commentary
Organism
Structure
1.18.6.1
N2
inhibits C2H2 reduction of mutant H195Q; maximal inhibition of H2 production at Fe protein to MoFe protein ration 2.5
Azotobacter vinelandii
1.18.6.1
N3-
inhibits H2 production competitively and reversibly
Azotobacter vinelandii
Ki Value [mM] (protein specific)
EC Number
Ki Value [mM]
Ki Value maximum [mM]
Inhibitor
Commentary
Organism
Structure
1.18.6.1
additional information
-
additional information
-
Azotobacter vinelandii
KM Value [mM] (protein specific)
EC Number
KM Value [mM]
KM Value Maximum [mM]
Substrate
Commentary
Organism
Structure
1.18.6.1
additional information
-
additional information
-
Azotobacter vinelandii
Metals/Ions (protein specific)
EC Number
Metals/Ions
Commentary
Organism
Structure
1.18.6.1
Mg2+
Mg2+ required for MgATP complex
Azotobacter vinelandii
Natural Substrates/ Products (Substrates) (protein specific)
EC Number
Natural Substrates
Organism
Commentary (Nat. Sub.)
Natural Products
Commentary (Nat. Pro.)
Organism (Nat. Pro.)
Reversibility
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
Azotobacter vinelandii
-
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
-
?
Purification (Commentary) (protein specific)
EC Number
Commentary
Organism
1.18.6.1
wild-type and mutant H195Q
Azotobacter vinelandii
Specific Activity [micromol/min/mg] (protein specific)
EC Number
Specific Activity Minimum [mol/min/mg]
Specific Activity Maximum [mol/min/mg]
Commentary
Organism
1.18.6.1
additional information
-
assay in anaerobic atmosphere required
Azotobacter vinelandii
1.18.6.1
0.024
-
purified mutant H195Q enzyme, anaerobic atmosphere
Azotobacter vinelandii
1.18.6.1
0.7
-
purified enzyme, anaerobic atmosphere
Azotobacter vinelandii
Substrates and Products (Substrate) (protein specific)
EC Number
Substrates
Commentary Substrates
Literature (Substrates)
Organism
Products
Commentary (Products)
Literature (Products)
Organism (Products)
Reversibility
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
-
440184
Azotobacter vinelandii
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
-
-
?
1.18.6.1
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
-
440184
Azotobacter vinelandii
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
-
440184
Azotobacter vinelandii
?
1.18.6.1
reduced ferredoxin + H+ + ATP
-
440184
Azotobacter vinelandii
oxidized ferredoxin + H2 + ADP + phosphate
-
440184
Azotobacter vinelandii
?
1.18.6.1
reduced ferredoxin + H+ + N3- + ATP
mutant H195Q shows only about 7.5% activity compared to wild-type
440184
Azotobacter vinelandii
oxidized ferredoxin + NH3 + N2 + ADP + phosphate
-
440184
Azotobacter vinelandii
?
Temperature Optimum [C] (protein specific)
EC Number
Temperature Optimum [C]
Temperature Optimum Maximum [C]
Commentary
Organism
1.18.6.1
additional information
-
-
Azotobacter vinelandii
Temperature Range [C] (protein specific)
EC Number
Temperature Minimum [C]
Temperature Maximum [C]
Commentary
Organism
1.18.6.1
13
45
-
Azotobacter vinelandii