ID   NAPB_AZOBR              Reviewed;         160 AA.
AC   Q8VU46;
DT   16-MAY-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2002, sequence version 1.
DT   03-AUG-2022, entry version 59.
DE   RecName: Full=Periplasmic nitrate reductase, electron transfer subunit;
DE   AltName: Full=Diheme cytochrome c NapB {ECO:0000250|UniProtKB:Q56351};
DE   Flags: Precursor;
GN   Name=napB {ECO:0000312|EMBL:AAL36491.1};
OS   Azospirillum brasilense.
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodospirillales;
OC   Azospirillaceae; Azospirillum.
OX   NCBI_TaxID=192;
RN   [1] {ECO:0000305, ECO:0000312|EMBL:AAL36491.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, AND SUBCELLULAR LOCATION.
RC   STRAIN=Sp245 {ECO:0000312|EMBL:AAL36491.1};
RX   PubMed=11409544; DOI=10.1007/s002030100271;
RA   Steenhoudt O., Keijers V., Okon Y., Vanderleyden J.;
RT   "Identification and characterization of a periplasmic nitrate reductase in
RT   Azospirillum brasilense Sp245.";
RL   Arch. Microbiol. 175:344-352(2001).
CC   -!- FUNCTION: Electron transfer subunit of the periplasmic nitrate
CC       reductase complex NapAB. Receives electrons from the membrane-anchored
CC       tetraheme c-type NapC protein and transfers these to NapA subunit, thus
CC       allowing electron flow between membrane and periplasm. Essential for
CC       periplasmic nitrate reduction with nitrate as the terminal electron
CC       acceptor. {ECO:0000269|PubMed:11409544}.
CC   -!- SUBUNIT: Component of the periplasmic nitrate reductase NapAB complex
CC       composed of NapA and NapB. {ECO:0000250|UniProtKB:Q56351}.
CC   -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000269|PubMed:11409544}.
CC   -!- PTM: Binds 2 heme C groups per subunit. {ECO:0000250|UniProtKB:Q56351}.
CC   -!- SIMILARITY: Belongs to the NapB family. {ECO:0000255}.
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DR   EMBL; AF245096; AAL36491.1; -; Genomic_DNA.
DR   RefSeq; WP_014200143.1; NZ_VITG01000024.1.
DR   AlphaFoldDB; Q8VU46; -.
DR   SMR; Q8VU46; -.
DR   PRIDE; Q8VU46; -.
DR   GO; GO:0042597; C:periplasmic space; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0009061; P:anaerobic respiration; IEA:InterPro.
DR   InterPro; IPR036280; Multihaem_cyt_sf.
DR   InterPro; IPR005591; NapB.
DR   PANTHER; PTHR38604; PTHR38604; 1.
DR   Pfam; PF03892; NapB; 1.
DR   PIRSF; PIRSF006105; NapB; 1.
DR   SUPFAM; SSF48695; SSF48695; 1.
DR   PROSITE; PS51008; MULTIHEME_CYTC; 1.
PE   3: Inferred from homology;
KW   Electron transport; Heme; Iron; Metal-binding; Periplasm; Signal;
KW   Transport.
FT   SIGNAL          1..25
FT                   /evidence="ECO:0000255"
FT   CHAIN           26..160
FT                   /note="Periplasmic nitrate reductase, electron transfer
FT                   subunit"
FT                   /id="PRO_0000417031"
FT   BINDING         73
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         87
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /note="covalent"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         90
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /note="covalent"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         91
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         108
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         127
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /note="covalent"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         130
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /note="covalent"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
FT   BINDING         131
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /ligand_part="Fe"
FT                   /ligand_part_id="ChEBI:CHEBI:18248"
FT                   /note="axial binding residue"
FT                   /evidence="ECO:0000250|UniProtKB:P44654"
SQ   SEQUENCE   160 AA;  17386 MW;  5925CE17F3BDE4A3 CRC64;
     MKTRIIFAAL ALAAAMPLLV SGVFAADGAA PAKVPSGPHP ITQEIPADPM AKEITDDHKR
     ARNYADQPPL IPHAIRDYQI DLNINKCMTC HDRKNTEGSQ APMISVTHFQ DRDGQTLGAV
     SPRRYFCTQC HVPQTDAQPI TGNRFRDIDS ILAGGKEGAK