ID   NARB_SYNY3              Reviewed;         714 AA.
AC   P73448;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   04-NOV-2026, entry version 154.
DE   RecName: Full=Nitrate reductase;
DE            EC=1.7.5.1;
GN   Name=narB; OrderedLocusNames=sll1454;
OS   Synechocystis sp. (strain ATCC 27184 / PCC 6803 / Kazusa).
OC   Bacteria; Bacillati; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Merismopediaceae; Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(1996).
CC   -!- FUNCTION: Nitrate reductase is a key enzyme involved in the first step
CC       of nitrate assimilation in plants, fungi and bacteria.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=nitrate + a quinol = a quinone + nitrite + H2O;
CC         Xref=Rhea:RHEA:56144, ChEBI:CHEBI:15377, ChEBI:CHEBI:16301,
CC         ChEBI:CHEBI:17632, ChEBI:CHEBI:24646, ChEBI:CHEBI:132124; EC=1.7.5.1;
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000305};
CC       Note=Binds 1 [4Fe-4S] cluster. {ECO:0000305};
CC   -!- COFACTOR:
CC       Name=Mo-bis(molybdopterin guanine dinucleotide);
CC         Xref=ChEBI:CHEBI:60539; Evidence={ECO:0000250};
CC       Note=Binds 1 molybdenum-bis(molybdopterin guanine dinucleotide) (Mo-
CC       bis-MGD) cofactor per subunit. {ECO:0000250};
CC   -!- PATHWAY: Nitrogen metabolism; nitrate reduction (denitrification);
CC       dinitrogen from nitrate: step 1/4.
CC   -!- SIMILARITY: Belongs to the prokaryotic molybdopterin-containing
CC       oxidoreductase family. NasA/NapA/NarB subfamily. {ECO:0000305}.
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DR   EMBL; BA000022; BAA17488.1; -; Genomic_DNA.
DR   PIR; S77385; S77385.
DR   AlphaFoldDB; P73448; -.
DR   SMR; P73448; -.
DR   FunCoup; P73448; 398.
DR   IntAct; P73448; 7.
DR   STRING; 1148.gene:10498353; -.
DR   PaxDb; 1148-gene:10498353; -.
DR   EnsemblBacteria; BAA17488; BAA17488; BAA17488.
DR   KEGG; syn:sll1454; -.
DR   eggNOG; COG0243; Bacteria.
DR   InParanoid; P73448; -.
DR   OMA; AACQINN; -.
DR   PhylomeDB; P73448; -.
DR   UniPathway; UPA00652; UER00706.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0009326; C:formate dehydrogenase complex; IBA:GO_Central.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:InterPro.
DR   GO; GO:0009055; F:electron transfer activity; IBA:GO_Central.
DR   GO; GO:0036397; F:formate dehydrogenase (quinone) activity; IBA:GO_Central.
DR   GO; GO:0043546; F:molybdopterin cofactor binding; IEA:InterPro.
DR   GO; GO:0160182; F:nitrate reductase (quinone) activity; IEA:UniProtKB-EC.
DR   GO; GO:0009061; P:anaerobic respiration; IBA:GO_Central.
DR   GO; GO:0019333; P:denitrification pathway; IEA:UniProtKB-UniPathway.
DR   GO; GO:0015944; P:formate oxidation; IBA:GO_Central.
DR   CDD; cd02791; MopB_CT_Nitrate-R-NapA-like; 1.
DR   CDD; cd02754; MopB_Nitrate-R-NapA-like; 1.
DR   FunFam; 2.20.25.90:FF:000006; Formate dehydrogenase alpha subunit; 1.
DR   FunFam; 3.40.228.10:FF:000002; Formate dehydrogenase subunit alpha; 1.
DR   FunFam; 2.40.40.20:FF:000005; Periplasmic nitrate reductase; 1.
DR   Gene3D; 2.40.40.20; -; 1.
DR   Gene3D; 3.40.50.740; -; 1.
DR   Gene3D; 2.20.25.90; ADC-like domains; 1.
DR   Gene3D; 3.40.228.10; Dimethylsulfoxide Reductase, domain 2; 1.
DR   InterPro; IPR009010; Asp_de-COase-like_dom_sf.
DR   InterPro; IPR041957; CT_Nitrate-R-NapA-like.
DR   InterPro; IPR006657; MoPterin_dinucl-bd_dom.
DR   InterPro; IPR006656; Mopterin_OxRdtase.
DR   InterPro; IPR006963; Mopterin_OxRdtase_4Fe-4S_dom.
DR   InterPro; IPR027467; MopterinOxRdtase_cofactor_BS.
DR   PANTHER; PTHR43105:SF9; NADPH-FE(3+) OXIDOREDUCTASE SUBUNIT ALPHA; 1.
DR   PANTHER; PTHR43105; RESPIRATORY NITRATE REDUCTASE; 1.
DR   Pfam; PF04879; Molybdop_Fe4S4; 1.
DR   Pfam; PF00384; Molybdopterin; 1.
DR   Pfam; PF01568; Molydop_binding; 1.
DR   SMART; SM00926; Molybdop_Fe4S4; 1.
DR   SUPFAM; SSF50692; ADC-like; 1.
DR   SUPFAM; SSF53706; Formate dehydrogenase/DMSO reductase, domains 1-3; 1.
DR   PROSITE; PS51669; 4FE4S_MOW_BIS_MGD; 1.
DR   PROSITE; PS00551; MOLYBDOPTERIN_PROK_1; 1.
PE   3: Inferred from homology;
KW   4Fe-4S; Iron; Iron-sulfur; Metal-binding; Molybdenum; Nitrate assimilation;
KW   Oxidoreductase; Reference proteome.
FT   CHAIN           1..714
FT                   /note="Nitrate reductase"
FT                   /id="PRO_0000063238"
FT   DOMAIN          7..70
FT                   /note="4Fe-4S Mo/W bis-MGD-type"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01004"
FT   BINDING         14
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01004"
FT   BINDING         17
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01004"
FT   BINDING         21
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01004"
FT   BINDING         56
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01004"
SQ   SEQUENCE   714 AA;  79632 MW;  702AA57ED9E605AA CRC64;
     MDSPAILPTT RTLCPYCGVG CGLEAVASPQ KSVVDAGHAH KIRGDRQHPS SQGMVCVKGA
     TVMESMDKQR LLYPMFRSSL DQPWQQISWE AALEIVVDKI QQVKQTLGVS GLCMYASGQM
     QTEDYYVAQK LFKGCLGTNN FDTNSRLCMS SAVSAYSLSF GSDGPPCCYE DLEITDCAFL
     IGTNTADCHP IIFNRLRKHH KQNPHVKLIV VDPRCTATAE VADLHLAINP GSDITLLHGI
     AYLLKKWNLI DQKFIDNHTQ DFEQYCQVID HYPPEKVTQI CGISLEQLET AAHYWGNAKT
     VLSLWSMGMN QSFQGTAKGR CLINLHLLTG QIGKPGSGPF SLTGQPNAMG GREAGGLSHL
     LPGYRSIKNP QHRQEVEQLW QISPGRINPE PGLSAWEMFM GLENQQVGFL WIVATNPVVS
     MPDLERVKKA LQQSTFTIHQ DAYSPTETAE YAHLLLPAAQ WSEKTGTMTN SERRVTLSPA
     FRSPPGEARP DWEIFAEVGR RLGFENQFNF VDSAAVHREY VQLTAERLCD QSGVSYEKLQ
     KLGPLQWPCR QSDQESQLLS TKRLYTDYKF CTENGRANFC LDHSRGLAEP VDPNYPFVLT
     NGRLYGHWHT QTRTGHIEKI KKMHPKPILE MHPKDAEKLG IKSQDLVAIK SRRGSAQLEV
     LVTRAIAPGT VFMPMHWGFL WDDNAEVNSL THATACPISK QPELKACAVN ITPV
//