ID   NIFK_METMP              Reviewed;         462 AA.
AC   P0CW53; P71527;
DT   03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   03-MAY-2011, sequence version 1.
DT   03-AUG-2022, entry version 45.
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; OrderedLocusNames=MMP0857;
OS   Methanococcus maripaludis (strain S2 / LL).
OC   Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC   Methanococcaceae; Methanococcus.
OX   NCBI_TaxID=267377;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=S2 / LL;
RX   PubMed=15466049; DOI=10.1128/jb.186.20.6956-6969.2004;
RA   Hendrickson E.L., Kaul R., Zhou Y., Bovee D., Chapman P., Chung J.,
RA   Conway de Macario E., Dodsworth J.A., Gillett W., Graham D.E., Hackett M.,
RA   Haydock A.K., Kang A., Land M.L., Levy R., Lie T.J., Major T.A.,
RA   Moore B.C., Porat I., Palmeiri A., Rouse G., Saenphimmachak C., Soell D.,
RA   Van Dien S., Wang T., Whitman W.B., Xia Q., Zhang Y., Larimer F.W.,
RA   Olson M.V., Leigh J.A.;
RT   "Complete genome sequence of the genetically tractable hydrogenotrophic
RT   methanogen Methanococcus maripaludis.";
RL   J. Bacteriol. 186:6956-6969(2004).
CC   -!- FUNCTION: This molybdenum-iron protein is part of the nitrogenase
CC       complex that catalyzes the key enzymatic reactions in nitrogen
CC       fixation. {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=[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) (By similarity).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the NifD/NifK/NifE/NifN family. {ECO:0000305}.
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DR   EMBL; BX950229; CAF30413.1; -; Genomic_DNA.
DR   RefSeq; WP_011170801.1; NC_005791.1.
DR   AlphaFoldDB; P0CW53; -.
DR   SMR; P0CW53; -.
DR   STRING; 267377.MMP0857; -.
DR   EnsemblBacteria; CAF30413; CAF30413; MMP0857.
DR   GeneID; 37875414; -.
DR   KEGG; mmp:MMP0857; -.
DR   PATRIC; fig|267377.15.peg.882; -.
DR   eggNOG; arCOG00593; Archaea.
DR   HOGENOM; CLU_025876_2_0_2; -.
DR   OMA; GLNNMID; -.
DR   OrthoDB; 15283at2157; -.
DR   BioCyc; MMAR267377:MMP_RS04460-MON; -.
DR   Proteomes; UP000000590; Chromosome.
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   Pfam; PF00148; Oxidored_nitro; 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; Nitrogen fixation;
KW   Nucleotide-binding; Oxidoreductase; Reference proteome.
FT   CHAIN           1..462
FT                   /note="Nitrogenase molybdenum-iron protein beta chain"
FT                   /id="PRO_0000408203"
FT   BINDING         21
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         46
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         104
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         145
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   462 AA;  50503 MW;  FA4DF212C3D57FD8 CRC64;
     MSELNVIKKE RTAVINPIVT CQPLGAMYAV SGIERGMPLV HGSQGCSTFV RYGFARHFRE
     PADIAVTSLH EDAAVFGGRK NLISGLGNLA ARFKPDVMGV VTTCSSEIIG DDVAGFIKTA
     KVEIAKKMGE EAANKIKIVQ INTPSFVEHQ FKGYDNAIKA IVDTLAEPKD EENGKLNIIP
     GIVNPGDIRE IKHMLSLMGV EGILLTDTSD PFDSPLRPSK ADKNPYYQKG GTPLADLQDC
     ANSLGTISLA NYANSAPASL EKKYNMPSKV SEAPIGIQNT DSFIRTVKKF TGNDVTDEIL
     DERGIVIDAM ADVASRYLFG RKVAIYGDPS ITVGMARFVA ELGMIPKVVC TGVKNEYFVN
     DLKKVAKESD EDIDALFGQD LRALDVYLKE NPVDLMIGSS DGRLMAKDLG IPLYRVGYPV
     YDRVGYQRRP IIGYNGALNL VDGITNTILD KYYETQDWKL QQ