ID   NAPB_HAEIN              Reviewed;         150 AA.
AC   P44654;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   27-MAR-2024, entry version 143.
DE   RecName: Full=Periplasmic nitrate reductase, electron transfer subunit;
DE   AltName: Full=Diheme cytochrome c NapB;
DE   Flags: Precursor;
GN   Name=napB; OrderedLocusNames=HI_0347;
OS   Haemophilus influenzae (strain ATCC 51907 / DSM 11121 / KW20 / Rd).
OC   Bacteria; Pseudomonadota; Gammaproteobacteria; Pasteurellales;
OC   Pasteurellaceae; Haemophilus.
OX   NCBI_TaxID=71421;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 51907 / DSM 11121 / KW20 / Rd;
RX   PubMed=7542800; DOI=10.1126/science.7542800;
RA   Fleischmann R.D., Adams M.D., White O., Clayton R.A., Kirkness E.F.,
RA   Kerlavage A.R., Bult C.J., Tomb J.-F., Dougherty B.A., Merrick J.M.,
RA   McKenney K., Sutton G.G., FitzHugh W., Fields C.A., Gocayne J.D.,
RA   Scott J.D., Shirley R., Liu L.-I., Glodek A., Kelley J.M., Weidman J.F.,
RA   Phillips C.A., Spriggs T., Hedblom E., Cotton M.D., Utterback T.R.,
RA   Hanna M.C., Nguyen D.T., Saudek D.M., Brandon R.C., Fine L.D.,
RA   Fritchman J.L., Fuhrmann J.L., Geoghagen N.S.M., Gnehm C.L., McDonald L.A.,
RA   Small K.V., Fraser C.M., Smith H.O., Venter J.C.;
RT   "Whole-genome random sequencing and assembly of Haemophilus influenzae
RT   Rd.";
RL   Science 269:496-512(1995).
RN   [2]
RP   PROTEIN SEQUENCE OF 27-31, FUNCTION, ABSORPTION SPECTROSCOPY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, SUBCELLULAR LOCATION, PTM, AND
RP   IDENTIFICATION BY MASS SPECTROMETRY.
RC   STRAIN=ATCC 51907 / DSM 11121 / KW20 / Rd;
RX   PubMed=11389694; DOI=10.1042/0264-6021:3560851;
RA   Brige A., Cole J.A., Hagen W.R., Guisez Y., Van Beeumen J.J.;
RT   "Overproduction, purification and novel redox properties of the dihaem
RT   cytochrome c, NapB, from Haemophilus influenzae.";
RL   Biochem. J. 356:851-858(2001).
RN   [3]
RP   CRYSTALLIZATION, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   STRAIN=ATCC 51907 / DSM 11121 / KW20 / Rd;
RX   PubMed=11223519; DOI=10.1107/s0907444900018011;
RA   Brige A., Leys D., Van Beeumen J.J.;
RT   "Crystallization and preliminary X-ray analysis of the recombinant dihaem
RT   cytochrome c (NapB) from Haemophilus influenzae.";
RL   Acta Crystallogr. D 57:418-420(2001).
RN   [4]
RP   X-RAY CRYSTALLOGRAPHY (1.25 ANGSTROMS) OF 28-150 IN COMPLEX WITH HEME C,
RP   AND PTM.
RC   STRAIN=ATCC 51907 / DSM 11121 / KW20 / Rd;
RX   PubMed=11939777; DOI=10.1021/bi012144b;
RA   Brige A., Leys D., Meyer T.E., Cusanovich M.A., Van Beeumen J.J.;
RT   "The 1.25 A resolution structure of the diheme NapB subunit of soluble
RT   nitrate reductase reveals a novel cytochrome c fold with a stacked heme
RT   arrangement.";
RL   Biochemistry 41:4827-4836(2002).
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:11389694}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Redox potential:
CC         E(0) are -25 mV and -175 mV. {ECO:0000269|PubMed:11389694};
CC   -!- SUBUNIT: Component of the periplasmic nitrate reductase NapAB complex
CC       composed of NapA and NapB. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Periplasm {ECO:0000269|PubMed:11223519,
CC       ECO:0000269|PubMed:11389694}.
CC   -!- PTM: Binds 2 heme C groups per subunit.
CC   -!- MASS SPECTROMETRY: Mass=14748.68; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:11223519};
CC   -!- SIMILARITY: Belongs to the NapB family. {ECO:0000305}.
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DR   EMBL; L42023; AAC22008.1; -; Genomic_DNA.
DR   PIR; C64149; C64149.
DR   RefSeq; NP_438511.1; NC_000907.1.
DR   PDB; 1JNI; X-ray; 1.25 A; A=28-150.
DR   PDBsum; 1JNI; -.
DR   AlphaFoldDB; P44654; -.
DR   SMR; P44654; -.
DR   STRING; 71421.HI_0347; -.
DR   EnsemblBacteria; AAC22008; AAC22008; HI_0347.
DR   KEGG; hin:HI_0347; -.
DR   PATRIC; fig|71421.8.peg.366; -.
DR   eggNOG; COG3043; Bacteria.
DR   HOGENOM; CLU_103367_3_0_6; -.
DR   OrthoDB; 13290at2; -.
DR   PhylomeDB; P44654; -.
DR   BioCyc; HINF71421:G1GJ1-363-MONOMER; -.
DR   EvolutionaryTrace; P44654; -.
DR   Proteomes; UP000000579; Chromosome.
DR   GO; GO:0042597; C:periplasmic space; IEA:UniProtKB-SubCell.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0060090; F:molecular adaptor activity; EXP:DisProt.
DR   GO; GO:0009061; P:anaerobic respiration; IBA:GO_Central.
DR   DisProt; DP00899; -.
DR   InterPro; IPR036280; Multihaem_cyt_sf.
DR   InterPro; IPR005591; NapB.
DR   PANTHER; PTHR38604; PERIPLASMIC NITRATE REDUCTASE, ELECTRON TRANSFER SUBUNIT; 1.
DR   PANTHER; PTHR38604:SF1; PERIPLASMIC NITRATE REDUCTASE, ELECTRON TRANSFER SUBUNIT; 1.
DR   Pfam; PF03892; NapB; 1.
DR   PIRSF; PIRSF006105; NapB; 1.
DR   SUPFAM; SSF48695; Multiheme cytochromes; 1.
DR   PROSITE; PS51008; MULTIHEME_CYTC; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Electron transport; Heme; Iron;
KW   Metal-binding; Periplasm; Reference proteome; Signal; Transport.
FT   SIGNAL          1..26
FT                   /evidence="ECO:0000269|PubMed:11389694"
FT   CHAIN           27..150
FT                   /note="Periplasmic nitrate reductase, electron transfer
FT                   subunit"
FT                   /id="PRO_0000006589"
FT   BINDING         70
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   BINDING         84
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /note="covalent"
FT                   /evidence="ECO:0000269|PubMed:11939777"
FT   BINDING         87
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="1"
FT                   /note="covalent"
FT                   /evidence="ECO:0000269|PubMed:11939777"
FT   BINDING         88
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   BINDING         105
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   BINDING         124
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /note="covalent"
FT                   /evidence="ECO:0000269|PubMed:11939777"
FT   BINDING         127
FT                   /ligand="heme c"
FT                   /ligand_id="ChEBI:CHEBI:61717"
FT                   /ligand_label="2"
FT                   /note="covalent"
FT                   /evidence="ECO:0000269|PubMed:11939777"
FT   BINDING         128
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   HELIX           85..88
FT                   /evidence="ECO:0007829|PDB:1JNI"
FT   TURN            90..92
FT                   /evidence="ECO:0007829|PDB:1JNI"
FT   HELIX           93..96
FT                   /evidence="ECO:0007829|PDB:1JNI"
FT   HELIX           103..105
FT                   /evidence="ECO:0007829|PDB:1JNI"
FT   HELIX           124..126
FT                   /evidence="ECO:0007829|PDB:1JNI"
SQ   SEQUENCE   150 AA;  16255 MW;  C5E98C4E1B29E01F CRC64;
     MINMTKQVSK ILAGLFTALF AGSLMASDAP AVGKDLTQAA ENIPPAFHNA PRQGELPALN
     YVNQPPMVPH SVANYQVTKN VNQCLNCHSP ENSRLSGATR ISPTHFMDRD GKVGSSSSPR
     RYFCLQCHVS QANVDPIVPN DFKPMKGYGN
//