ID   NIFK_FRAAL              Reviewed;         528 AA.
AC   Q57118;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   03-AUG-2022, entry version 79.
DE   RecName: Full=Nitrogenase molybdenum-iron protein beta chain;
DE            EC=1.18.6.1;
DE   AltName: Full=Dinitrogenase;
DE   AltName: Full=Nitrogenase component I;
GN   Name=nifK;
OS   Frankia alni.
OC   Bacteria; Actinobacteria; Frankiales; Frankiaceae; Frankia.
OX   NCBI_TaxID=1859;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ARI3;
RX   PubMed=8574444; DOI=10.1111/j.1365-294x.1995.tb00242.x;
RA   Nalin R., Domenach A.M., Normand P.;
RT   "Molecular structure of the Frankia spp. nifD-K intergenic spacer and
RT   design of Frankia genus compatible primer.";
RL   Mol. Ecol. 4:483-491(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ARI3;
RA   Specq A., Normand P.;
RL   Submitted (APR-1996) to the EMBL/GenBank/DDBJ databases.
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   -!- SUBUNIT: Tetramer of two alpha and two beta chains. Forms complex with
CC       the iron protein (nitrogenase component 2).
CC   -!- MISCELLANEOUS: Cys-194 is present instead of the usual Ser that serves
CC       as a ligand for the 8Fe-7S cluster in the oxidized state.
CC   -!- SIMILARITY: Belongs to the NifD/NifK/NifE/NifN family. {ECO:0000305}.
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DR   EMBL; L35557; AAB53116.1; -; Genomic_DNA.
DR   EMBL; L41344; AAA96264.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q57118; -.
DR   SMR; Q57118; -.
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   InterPro; IPR000510; Nase/OxRdtase_comp1.
DR   InterPro; IPR000318; Nase_comp1_CS.
DR   InterPro; IPR005976; Nase_Mo-Fe_CF_bsu.
DR   InterPro; IPR024564; Nase_Mo-Fe_CF_bsu_N.
DR   Pfam; PF11844; DUF3364; 1.
DR   Pfam; PF00148; Oxidored_nitro; 1.
DR   TIGRFAMs; TIGR01286; nifK; 1.
DR   PROSITE; PS00699; NITROGENASE_1_1; 1.
PE   3: Inferred from homology;
KW   ATP-binding; Iron; Iron-sulfur; Metal-binding; Nitrogen fixation;
KW   Nucleotide-binding; Oxidoreductase.
FT   CHAIN           1..528
FT                   /note="Nitrogenase molybdenum-iron protein beta chain"
FT                   /id="PRO_0000153099"
FT   BINDING         76
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with alpha chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         101
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with alpha chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         159
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with alpha chain"
FT                   /evidence="ECO:0000250"
FT   BINDING         194
FT                   /ligand="[8Fe-7S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:21143"
FT                   /ligand_note="ligand shared with alpha chain"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   528 AA;  58525 MW;  9BCAF68E99889DD2 CRC64;
     MTTTPEHTSA VPLRVLDHND IFRDEVYQKQ FEGKREFENA APKEEVQRVL DWTRGWEYRE
     KNFAREALTV NPAKACQPLG AVLAALGFEG TMPLVHGSQG CVAYFRSHFA RHFKEPVPAA
     STSMTEDAAV FGGINNLVEA MENITALYKP KHIAVSTTCM AEVIGEDLFA YIGAAREQEA
     ITQDFPVSYA HTPCFVGSHI TGYDVMLKGI LEMLAKSPDA DASKVAKSDK VRLNVIPGFD
     TYIGNHREYK RILELMGVDP LILGDHSSSL DSPADGEYDL YPGGTPLAEG ALAKFSRASL
     VLQESTLRRT AEYIEKDWKQ ETVLLETPLG VKGTDAFLTA VAKVAEVEVP AELTAERGRL
     VDAITDSHAY VHGKRVAIAG DPDLVIALTR FVLELGMIPV HIVSTNADTT FKARMEKVLS
     ASKFGEEATV WPEKDLWHLR SLVFTEPVDL LIGSMQLKYI SREANVPLVR VGFPIFDRHH
     LHRFPIIGYT GGLHLLTQLV NTILDEMDRN DPDHSFELRR RSLIGAAL