Information on EC 1.18.6.1 - nitrogenase

New: Word Map on EC 1.18.6.1
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Mark a special word or phrase in this record:
Search Reference ID:
Select one or more organisms in this record:
Show additional data
Do not include text mining results
Include (text mining) results (more...)
Include results (AMENDA + additional results, but less precise; more...)


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

EC NUMBER
COMMENTARY hide
1.18.6.1
-
RECOMMENDED NAME
GeneOntology No.
nitrogenase
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O = 8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
show the reaction diagram
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oxidation
-
-
-
-
redox reaction
-
-
-
-
reduction
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Chloroalkane and chloroalkene degradation
-
-
Metabolic pathways
-
-
Microbial metabolism in diverse environments
-
-
nitrate assimilation
-
-
nitrogen fixation I (ferredoxin)
-
-
Nitrogen metabolism
-
-
SYSTEMATIC NAME
IUBMB Comments
reduced ferredoxin:dinitrogen oxidoreductase (ATP-hydrolysing)
Requires Mg2+. It is composed of two proteins that can be separated but are both required for nitrogenase activity. Dinitrogen reductase is a [4Fe-4S] protein, which, with two molecules of ATP and ferredoxin, generates an electron. The electron is transferred to the other protein, dinitrogenase (molybdoferredoxin). Dinitrogenase is a molybdenum-iron protein that reduces dinitrogen in three succesive two-electron reductions from nitrogen to diimine to hydrazine to two molecules of ammonia. The molybdenum may be replaced by vanadium or iron. The reduction is initiated by formation of hydrogen in stoichiometric amounts [2]. Acetylene is reduced to ethylene (but only very slowly to ethane), azide to nitrogen and ammonia, and cyanide to methane and ammonia. In the absence of a suitable substrate, hydrogen is slowly formed. Ferredoxin may be replaced by flavodoxin [see EC 1.19.6.1 nitrogenase (flavodoxin)].
CAS REGISTRY NUMBER
COMMENTARY hide
9013-04-1
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
enzyme activity increases with increasing concentration of O2 in the root zone. Photosynthetic rate, plant dry mass, leaf N content, and nodule fresh mass are maximal in plants maintained with 15-25% O2 in the root zone
-
-
Manually annotated by BRENDA team
Anabaena sp. PCC 7120
-
-
-
Manually annotated by BRENDA team
strain BH72
-
-
Manually annotated by BRENDA team
strain BH72
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
contains Mo- and V-nitrogenases
-
-
Manually annotated by BRENDA team
Azotobacter sp.
-
-
-
Manually annotated by BRENDA team
strain DJ
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
strain DJ1310
-
-
Manually annotated by BRENDA team
strain B18LD
-
-
Manually annotated by BRENDA team
strain B18LD
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Chromatium sp.
-
-
-
Manually annotated by BRENDA team
301
-
-
Manually annotated by BRENDA team
a marine unicellular diazotrophic cyanobacterium
-
-
Manually annotated by BRENDA team
a marine unicellular diazotrophic cyanobacterium
-
-
Manually annotated by BRENDA team
Cyanobacterium sp.
-
-
-
Manually annotated by BRENDA team
low activity
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
C-M 74
-
-
Manually annotated by BRENDA team
C-M 74
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Gloeocapsa sp.
-
-
-
Manually annotated by BRENDA team
a terrestrial unicellular diazotrophic cyanobacterium
-
-
Manually annotated by BRENDA team
strain PAL-5, in endosymbiosis with sugarcane, Saccharum officinarum
-
-
Manually annotated by BRENDA team
strain M5a1
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
inoculated with symbiont Mesorhizobium loti strain New Zealand Palmerston 2235
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
NifH2 is one of two homologues of NifH in Methanocaldococcus jannaschii
-
-
Manually annotated by BRENDA team
strain Y1
-
-
Manually annotated by BRENDA team
strain Y1
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
-
-
-
Manually annotated by BRENDA team
Rhizobium lupini
ORS571
-
-
Manually annotated by BRENDA team
strain B10S
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
metabolism
physiological function
additional information
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
(VO4)3- + ?
(VO2)+ + ?
show the reaction diagram
-
reduction of vanadium(V) by reduced Fe-protein of enzyme to vanadium(IV), which then probably binds to the nucleotide binding site in place of the Mg2+ which is normally present. The oxidized Fe-protein is unable to reduce vanadate
-
-
?
2 reduced ferredoxin + 2 H+ + acetylene + 2 ATP + 2 H2O
2 oxidized ferredoxin + ethylene + 2 ADP + 2 phosphate
show the reaction diagram
3,3-difluorocyclopropene + dithionite
propene + 2-fluoropropene + ?
show the reaction diagram
6 reduced flavodoxin + N2 + 6 H2O + 6 ATP
6 oxidized flavodoxin + 2 NH3 + 6 H+ + 6 ADP + 6 phosphate
show the reaction diagram
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
show the reaction diagram
acetylene + ?
ethylene + ?
show the reaction diagram
C2H2 + ?
?
show the reaction diagram
C2H2 + ?
H2 + ?
show the reaction diagram
-
-
-
-
?
CN- + europium(II) diethylenetriaminepentaacetate + H+
?
show the reaction diagram
CO + dithionite + H+
CH4 + C2H6 + C2H4 + C3H6 + C3H8 + ?
show the reaction diagram
CO + europium(II) diethylenetriaminepentaacetate + H+
?
show the reaction diagram
CS2 + ?
H2S + ?
show the reaction diagram
slow turnover
-
-
?
cyanamide + ?
?
show the reaction diagram
-
-
-
?
cyanide + ?
?
show the reaction diagram
cyclopropene + ?
?
show the reaction diagram
diazene + ?
?
show the reaction diagram
dithionite + H+ + acetylene + ATP
?
show the reaction diagram
dithionite + H+ + N2 + ATP
?
show the reaction diagram
ethylene + ?
?
show the reaction diagram
hydrazine + ?
?
show the reaction diagram
methyl isocyanide + ?
?
show the reaction diagram
methyldiazene + ?
?
show the reaction diagram
N2 + 8 e- + 16 ATP + 8 H+
2 NH3 + H2 + 16 ADP + 16 phosphate
show the reaction diagram
N2 + 8 e- + 8 H+ + 16 ATP
2 NH3 + H2 + 16 ADP + 16 phosphate
show the reaction diagram
N2H4 + ?
?
show the reaction diagram
-
-
-
?
N2O + ?
?
show the reaction diagram
N3- + ?
?
show the reaction diagram
propargyl alcohol + ?
?
show the reaction diagram
reduced ferredoxin + H+ + ATP
oxidized ferredoxin + H2 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + CH3NC + ATP
oxidized ferredoxin + CH4 + C2H4 + C3H6 + C3H8 + CH3NH2 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + CN- + ATP
oxidized ferredoxin + CH4 + NH3 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + N2 + ATP
oxidized ferredoxin + H2 + NH3 + ADP + phosphate
show the reaction diagram
-
-
-
-
?
reduced ferredoxin + H+ + N2 + ATP + H2O
oxidized ferredoxin + H2 + NH3 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + N2O + ATP
oxidized ferredoxin + H2O + N2 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + N3- + ATP
oxidized ferredoxin + NH3 + N2 + ADP + phosphate
show the reaction diagram
reduced ferredoxin + H+ + SCN- + ATP
oxidized ferredoxin + H2S + HCN + ADP + phosphate
show the reaction diagram
-
-
-
?
Ti3+ + H+ + N2 + ATP
?
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
2 reduced ferredoxin + 2 H+ + acetylene + 2 ATP + 2 H2O
2 oxidized ferredoxin + ethylene + 2 ADP + 2 phosphate
show the reaction diagram
8 reduced ferredoxin + 8 H+ + N2 + 16 ATP + 16 H2O
8 oxidized ferredoxin + H2 + 2 NH3 + 16 ADP + 16 phosphate
show the reaction diagram
N2 + 8 e- + 16 ATP + 8 H+
2 NH3 + H2 + 16 ADP + 16 phosphate
show the reaction diagram
-
the enzyme is responsible for biological nitrogen fixation, the conversion of atmospheric N2 to NH3
-
-
?
N2 + 8 e- + 8 H+ + 16 ATP
2 NH3 + H2 + 16 ADP + 16 phosphate
show the reaction diagram
-
-
-
-
ir
reduced ferredoxin + H+ + N2 + ATP
oxidized ferredoxin + H2 + NH3 + ADP + phosphate
show the reaction diagram
-
-
-
-
?
reduced ferredoxin + H+ + N2 + ATP + H2O
oxidized ferredoxin + H2 + NH3 + ADP + phosphate
show the reaction diagram
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
FeMo cofactor
FeMo protein
Ferredoxin
iron cofactor
-
the Fe protein is a homodimer containing a single [4Fe-4S] cluster and functions as an ATP-dependent electron donor to the MoFe protein
-
iron-molybdenum cofactor
iron-vanadium cofactor
-
i.e. FeVco cofactor, in the V-nitrogenase
-
MgATP2-
-
required
[4Fe-4S]-center
-
NifB and NifEN are two essential elements immediately adjacent to each other along the biosynthetic pathway of FeMoco. The 8Fe-precursor is present in the NifEN entity of a synthetic NifEN-B fusion protein, and additional [Fe4S4]-type cluster species are present in the NifB entity of NifEN-B. The cluster species in NifEN-B consist of both SAM-motif- and non-SAM-motif-bound [Fe4S4]-type clusters. The non-SAM-motif [Fe4S4]-cluster is a NifB-bound intermediate of FeMoco assembly, which could be converted to the 8Fe-precursor in a SAM-dependent mechanism
additional information
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY