ID   NIFD_AZOBR              Reviewed;         482 AA.
AC   P25313;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   03-AUG-2022, entry version 86.
DE   RecName: Full=Nitrogenase molybdenum-iron protein alpha chain;
DE            EC=1.18.6.1;
DE   AltName: Full=Dinitrogenase;
DE   AltName: Full=Nitrogenase component I;
GN   Name=nifD;
OS   Azospirillum brasilense.
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodospirillales;
OC   Azospirillaceae; Azospirillum.
OX   NCBI_TaxID=192;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=1823284;
RA   Passaglia L.M.P., Nunes C.P., Zaha A., Schrank I.S.;
RT   "The nifHDK operon in the free-living nitrogen-fixing bacteria Azospirillum
RT   brasilense sequentially comprises genes H, D, K, an 353 bp orf and gene
RT   Y.";
RL   Braz. J. Med. Biol. Res. 24:649-675(1991).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-28.
RC   STRAIN=ATCC 29145 / DSM 1690 / IMET 11303 / Sp7;
RX   PubMed=2608030; DOI=10.1007/bf00260861;
RA   de Zamaroczy M., Delorme F., Elmerich C.;
RT   "Regulation of transcription and promoter mapping of the structural genes
RT   for nitrogenase (nifHDK) of Azospirillum brasilense Sp7.";
RL   Mol. Gen. Genet. 220:88-94(1989).
CC   -!- FUNCTION: This molybdenum-iron protein is part of the nitrogenase
CC       complex that catalyzes the key enzymatic reactions in nitrogen
CC       fixation.
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=[8Fe-7S] cluster; Xref=ChEBI:CHEBI:21143; Evidence={ECO:0000250};
CC       Note=Binds 1 [8Fe-7S] cluster per heterodimer. {ECO:0000250};
CC   -!- COFACTOR:
CC       Name=[7Fe-Mo-9S-C-homocitryl] cluster; Xref=ChEBI:CHEBI:30409;
CC         Evidence={ECO:0000250};
CC       Note=Binds 1 [7Fe-Mo-9S-C-homocitryl] cluster per subunit.
CC       {ECO:0000250};
CC   -!- SUBUNIT: Tetramer of two alpha and two beta chains. Forms complex with
CC       the iron protein (nitrogenase component 2).
CC   -!- SIMILARITY: Belongs to the NifD/NifK/NifE/NifN family. {ECO:0000305}.
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DR   EMBL; M64344; AAB02343.1; -; Genomic_DNA.
DR   EMBL; X51500; CAA35869.2; -; Genomic_DNA.
DR   PIR; S27474; S15748.
DR   AlphaFoldDB; P25313; -.
DR   SMR; P25313; -.
DR   GO; GO:0016612; C:molybdenum-iron nitrogenase complex; IEA:InterPro.
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:0051536; F:iron-sulfur cluster binding; IEA:UniProtKB-KW.
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   CDD; cd01976; Nitrogenase_MoFe_alpha; 1.
DR   InterPro; IPR000510; Nase/OxRdtase_comp1.
DR   InterPro; IPR010143; Nase_comp1_asu.
DR   InterPro; IPR000318; Nase_comp1_CS.
DR   InterPro; IPR005972; Nase_Mo-Fe_asu.
DR   PANTHER; PTHR43457; PTHR43457; 1.
DR   Pfam; PF00148; Oxidored_nitro; 1.
DR   TIGRFAMs; TIGR01862; N2-ase-Ialpha; 1.
DR   TIGRFAMs; TIGR01282; nifD; 1.
DR   PROSITE; PS00699; NITROGENASE_1_1; 1.
DR   PROSITE; PS00090; NITROGENASE_1_2; 1.
PE   3: Inferred from homology;
KW   ATP-binding; Iron; Iron-sulfur; Metal-binding; Molybdenum;
KW   Nitrogen fixation; Nucleotide-binding; Oxidoreductase.
FT   CHAIN           1..482
FT                   /note="Nitrogenase molybdenum-iron protein alpha chain"
FT                   /id="PRO_0000153054"
FT   BINDING         62
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with beta chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         88
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with beta chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         154
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with beta chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         445
FT                   /ligand="[7Fe-Mo-9S-C-homocitryl] cluster"
FT                   /ligand_id="ChEBI:CHEBI:30409"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   482 AA;  53902 MW;  FC43D87490BBD39B CRC64;
     MSLSVNEGVD VKGLVDKVLE AYPEKSRRRR AKHLNVLEAE AKDCGVKSNI KSIPGVMTIR
     GCAYAGSKGV VWGPIKDMIH ISHGPVGCGY YSWSGRRNYY VGDTGVDKLG TMHFTSDFQE
     KDIVFGGDKK LHKVIEEINE LFPLVNGISI QSECPIGLNG DDIEGVSKAK SEELGKPVVP
     VRCEGFRGVS QSLGHHIAND VIRDWILPKK TEPKEGFVST PYDVTIIGDY NIGGDAWASR
     ILLEEIGLRV IAQWSGDGTL AELENQPKAK VNLIHSYRSM NYIARHMEEK FGIPWMEYNF
     FGPSQIAESL RKIAALFDDT IKENAEKVIA KYQPMVDAVV GDAALRAHGT KGRVPLKPLG
     PRHRPIVDAY HDLGMEIVGT GYEFAHNDDY QRTQHYVKEG TLIYDDVTAF ELEKFVELMR
     PDLVASGIKE KYVFQKMGLP FRQMHSWDYS GPYHGYDGFA IFARDMDLAI NNPVWGIMKA
     PF