ID   NIFD_METTL              Reviewed;         478 AA.
AC   P20620;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1991, sequence version 1.
DT   03-AUG-2022, entry version 81.
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   Methanothermococcus thermolithotrophicus (Methanococcus
OS   thermolithotrophicus).
OC   Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC   Methanococcaceae; Methanothermococcus.
OX   NCBI_TaxID=2186;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2503679; DOI=10.1111/j.1365-2958.1989.tb00200.x;
RA   Souillard N., Sibold L.;
RT   "Primary structure, functional organization and expression of nitrogenase
RT   structural genes of the thermophilic archaebacterium Methanococcus
RT   thermolithotrophicus.";
RL   Mol. Microbiol. 3:541-551(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; X13830; CAA32058.1; -; Genomic_DNA.
DR   PIR; S06987; S06987.
DR   AlphaFoldDB; P20620; -.
DR   SMR; P20620; -.
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   InterPro; IPR000510; Nase/OxRdtase_comp1.
DR   InterPro; IPR010143; Nase_comp1_asu.
DR   InterPro; IPR000318; Nase_comp1_CS.
DR   PANTHER; PTHR43457; PTHR43457; 1.
DR   Pfam; PF00148; Oxidored_nitro; 1.
DR   TIGRFAMs; TIGR01862; N2-ase-Ialpha; 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..478
FT                   /note="Nitrogenase molybdenum-iron protein alpha chain"
FT                   /id="PRO_0000153075"
FT   BINDING         46
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         72
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         134
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         260
FT                   /ligand="[7Fe-Mo-9S-C-homocitryl] cluster"
FT                   /ligand_id="ChEBI:CHEBI:30409"
FT                   /evidence="ECO:0000250"
FT   BINDING         430
FT                   /ligand="[7Fe-Mo-9S-C-homocitryl] cluster"
FT                   /ligand_id="ChEBI:CHEBI:30409"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   478 AA;  54396 MW;  A854767E8E2D2F19 CRC64;
     MPYILLDCDK FIPERMKHTY VYDPEENILP ACNTNTVPGD MTERGCAFAG SRGVVGGPIK
     DAIHMVHGPI GCAYYTWGTR RALSDNEFHR RYCFCTDMQE SDIVYGGEKT LEKASLEVME
     EFPEASGTFI YTTCPTALIG DNVDAIARNI EKATKKPAIA INSPGFCGVS QSKGHHVFNM
     TFYKWLKLKR KEFPEKCMPE EEKTPYDVAL IGDYNMDWDV AVIKPLLEKI GCRYVTTFTG
     NASLDELFQL MDVKLNIVHC QRSAEYIAQM INDGFDIPYT RATFFGLSDI AESLYDVAKA
     LDLPKERVDQ VIKEEMEAIQ PKLDYYKSKL EGKTCMVYVG GPRTWHWIKA MKDLGVEYVA
     ACCTFSHTDD YEKMNKNFKE AGIKDILVID APNEPELEEA VKTLDPDFML VGLKERYLFR
     KYGVPTINSH SYEEGPYAGY RGFVNFARDV YKAVCHPVWN VLKEGEDKFK NFKGDLNE