ID   NIFH_NOSSN              Reviewed;          74 AA.
AC   P52336;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   03-AUG-2022, entry version 82.
DE   RecName: Full=Nitrogenase iron protein;
DE            EC=1.18.6.1;
DE   AltName: Full=Nitrogenase Fe protein;
DE   AltName: Full=Nitrogenase component II;
DE   AltName: Full=Nitrogenase reductase;
DE   Flags: Fragment;
GN   Name=nifH;
OS   Nostoc sp. (strain MUN 8820).
OC   Bacteria; Cyanobacteria; Nostocales; Nostocaceae; Nostoc.
OX   NCBI_TaxID=55397;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8932316; DOI=10.1128/jb.178.22.6587-6598.1996;
RA   Hill D.R., Belbin T.J., Thorsteinsson M.V., Bassam D., Brass S., Ernst A.,
RA   Boger P., Paerl H., Mulligan M.E., Potts M.;
RT   "GlbN (cyanoglobin) is a peripheral membrane protein that is restricted to
RT   certain Nostoc spp.";
RL   J. Bacteriol. 178:6587-6598(1996).
CC   -!- FUNCTION: The key enzymatic reactions in nitrogen fixation are
CC       catalyzed by the nitrogenase complex, which has 2 components: the iron
CC       protein and the molybdenum-iron protein. {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=16 ATP + 16 H2O + N2 + 8 reduced [2Fe-2S]-[ferredoxin] = 16
CC         ADP + 6 H(+) + H2 + 2 NH4(+) + 8 oxidized [2Fe-2S]-[ferredoxin] + 16
CC         phosphate; Xref=Rhea:RHEA:21448, Rhea:RHEA-COMP:10000, Rhea:RHEA-
CC         COMP:10001, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:17997,
CC         ChEBI:CHEBI:18276, ChEBI:CHEBI:28938, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:33737, ChEBI:CHEBI:33738, ChEBI:CHEBI:43474,
CC         ChEBI:CHEBI:456216; EC=1.18.6.1;
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000250};
CC       Note=Binds 1 [4Fe-4S] cluster per dimer. {ECO:0000250};
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the NifH/BchL/ChlL family. {ECO:0000305}.
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DR   EMBL; L47979; AAB41123.1; -; Genomic_DNA.
DR   AlphaFoldDB; P52336; -.
DR   SMR; P52336; -.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR   GO; GO:0018697; F:carbonyl sulfide nitrogenase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0016163; F:nitrogenase activity; IEA:UniProtKB-EC.
DR   GO; GO:0009399; P:nitrogen fixation; IEA:UniProtKB-KW.
DR   Gene3D; 3.40.50.300; -; 1.
DR   InterPro; IPR000392; NifH/frxC.
DR   InterPro; IPR027417; P-loop_NTPase.
DR   PANTHER; PTHR42864; PTHR42864; 1.
DR   Pfam; PF00142; Fer4_NifH; 1.
DR   SUPFAM; SSF52540; SSF52540; 1.
DR   PROSITE; PS51026; NIFH_FRXC_3; 1.
PE   3: Inferred from homology;
KW   4Fe-4S; ATP-binding; Iron; Iron-sulfur; Metal-binding; Nitrogen fixation;
KW   Nucleotide-binding; Oxidoreductase.
FT   CHAIN           1..>74
FT                   /note="Nitrogenase iron protein"
FT                   /id="PRO_0000139517"
FT   BINDING         13..20
FT                   /ligand="ATP"
FT                   /ligand_id="ChEBI:CHEBI:30616"
FT                   /evidence="ECO:0000255"
FT   NON_TER         74
SQ   SEQUENCE   74 AA;  7919 MW;  14B88F560242DCDE CRC64;
     MTDDNIRQIA FYGKGGIGKS TTSQNTLAAM AEMGQRILIV GCDPKADSTR LMLHSKAQTT
     VLHLAAERGA VEDI