ID   NIFK_BRASP              Reviewed;         513 AA.
AC   P06122;
DT   01-JAN-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1988, sequence version 1.
DT   03-AUG-2022, entry version 83.
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   Bradyrhizobium sp. (strain ANU 289).
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Hyphomicrobiales;
OC   Bradyrhizobiaceae; Bradyrhizobium; unclassified Bradyrhizobium.
OX   NCBI_TaxID=186901;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=6095197; DOI=10.1093/nar/12.22.8329;
RA   Weinman J.J., Fellows F.F., Gresshoff P.M., Shine J., Scott K.F.;
RT   "Structural analysis of the genes encoding the molybdenum-iron protein of
RT   nitrogenase in the Parasponia rhizobium strain ANU289.";
RL   Nucleic Acids Res. 12:8329-8344(1984).
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: Ala-184 is present instead of the usual Ser that would
CC       serve 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; X01139; CAA25597.1; -; Genomic_DNA.
DR   AlphaFoldDB; P06122; -.
DR   SMR; P06122; -.
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.
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..513
FT                   /note="Nitrogenase molybdenum-iron protein beta chain"
FT                   /id="PRO_0000153095"
FT   BINDING         68
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         93
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         150
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   513 AA;  56538 MW;  741373586CDD8A36 CRC64;
     MAQSADHVLD HLELFRGPEY QQMLADKKMF ENPRDPAEVE RIRAVTKTPE YREKNFAEAL
     AVNPAKACQP LGAVFVSVGF EGTLPFVHGS QGCVAYYRSH LSRHFKEPSS CVSSSMTEDA
     AVFGGLNNMI DGLANSYNMY KPKMICSTTC MAEVIGDDLN AFIKTSKEKG SVRRSSTPFA
     HTPAFVGSHV TGYDNALKGI LEHFWNGKAG TAPKLERKPN EAINIIGGFD GNTVGNLREI
     KRILALMGIK HTILADNSEV FDTPTDGEFR MYDGGTHVED TANAIHAKAT ISMQQWCTEK
     TLPFVSEHGQ DVVSFNYPVG VSATDDLLVA LSRISGKEIP EQLARERGRL VDAIADSSAH
     IHGKKFAIYG DPDLCYGLAA FLLELGAEPT HVLSTNGNNV AGENATLFAG SPFGELPAYP
     GRDLWHMRSL LFTEPVDFLI GNTHGKYLER DTGTPLIRIG FPIFDRHHHH RFPVWGYQGG
     LNVLVKILDK IFDEIDKKTS VLGKTDYSFD IIR