ID   NIFK_METMI              Reviewed;         462 AA.
AC   P0CW52; P71527;
DT   03-MAY-2011, integrated into UniProtKB/Swiss-Prot.
DT   03-MAY-2011, sequence version 1.
DT   03-AUG-2022, entry version 24.
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   Methanococcus maripaludis (Methanococcus deltae).
OC   Archaea; Euryarchaeota; Methanomada group; Methanococci; Methanococcales;
OC   Methanococcaceae; Methanococcus.
OX   NCBI_TaxID=39152;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 43000 / DSM 2067 / JCM 10722 / JJ;
RX   PubMed=8990309; DOI=10.1128/jb.179.2.541-543.1997;
RA   Kessler P.S., McLarnan J., Leigh J.A.;
RT   "Nitrogenase phylogeny and the molybdenum dependence of nitrogen fixation
RT   in Methanococcus maripaludis.";
RL   J. Bacteriol. 179:541-543(1997).
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   -!- SIMILARITY: Belongs to the NifD/NifK/NifE/NifN family. {ECO:0000305}.
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DR   EMBL; U75887; AAC45516.1; -; Genomic_DNA.
DR   PIR; T10094; T10094.
DR   AlphaFoldDB; P0CW52; -.
DR   SMR; P0CW52; -.
DR   DIP; DIP-61202N; -.
DR   IntAct; P0CW52; 3.
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.
FT   CHAIN           1..462
FT                   /note="Nitrogenase molybdenum-iron protein beta chain"
FT                   /id="PRO_0000153103"
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;  50475 MW;  2C445D1458279D52 CRC64;
     MSELNVITKE RTAVINPIVT CQPLGAMYAV SGIERGMPLV HGSQGCSTFV RYGFARHFRE
     PADIAVTSLH EDAAVFGGRK NLISGLGNLA ARFKPDVMGV VTTCSSEIIG DDVAGFIKTA
     KVEIAKKMGE EAANKIKIVQ INTPSFVEHQ FKGYDNAIKA IVDTLAEPKD EENGKLIIIP
     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