ID   NQO6_PARDE              Reviewed;         173 AA.
AC   P29918;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1993, sequence version 1.
DT   03-AUG-2022, entry version 97.
DE   RecName: Full=NADH-quinone oxidoreductase subunit 6;
DE            EC=7.1.1.-;
DE   AltName: Full=NADH dehydrogenase I subunit 6;
DE   AltName: Full=NDH-1 subunit 6;
GN   Name=nqo6;
OS   Paracoccus denitrificans.
OC   Bacteria; Proteobacteria; Alphaproteobacteria; Rhodobacterales;
OC   Rhodobacteraceae; Paracoccus.
OX   NCBI_TaxID=266;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 13543 / NRRL B-3784 / NRC 449;
RX   PubMed=1637825; DOI=10.1021/bi00145a009;
RA   Xu X., Matsuno-Yagi A., Yagi T.;
RT   "Gene cluster of the energy-transducing NADH-quinone oxidoreductase of
RT   Paracoccus denitrificans: characterization of four structural gene
RT   products.";
RL   Biochemistry 31:6925-6932(1992).
CC   -!- FUNCTION: NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur
CC       (Fe-S) centers, to quinones in the respiratory chain. The immediate
CC       electron acceptor for the enzyme in this species is believed to be
CC       ubiquinone. Couples the redox reaction to proton translocation (for
CC       every two electrons transferred, four hydrogen ions are translocated
CC       across the cytoplasmic membrane), and thus conserves the redox energy
CC       in a proton gradient.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a quinone + 5 H(+)(in) + NADH = a quinol + 4 H(+)(out) +
CC         NAD(+); Xref=Rhea:RHEA:57888, ChEBI:CHEBI:15378, ChEBI:CHEBI:24646,
CC         ChEBI:CHEBI:57540, ChEBI:CHEBI:57945, ChEBI:CHEBI:132124;
CC   -!- COFACTOR:
CC       Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883; Evidence={ECO:0000305};
CC       Note=Binds 1 [4Fe-4S] cluster. {ECO:0000305};
CC   -!- SUBUNIT: NDH-1 is composed of at least 14 different subunits, Nqo1 to
CC       Nqo14. The complex has a L-shaped structure, with the hydrophobic arm
CC       (subunits Nqo7, Nqo8, Nqo10 to Nqo14) embedded in the inner membrane
CC       and the hydrophilic peripheral arm (subunits Nqo1 to Nqo6, Nqo9)
CC       protruding into the bacterial cytoplasm. The hydrophilic domain
CC       contains all the redox centers.
CC   -!- SUBCELLULAR LOCATION: Cell inner membrane {ECO:0000305}; Peripheral
CC       membrane protein {ECO:0000305}; Cytoplasmic side {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the complex I 20 kDa subunit family.
CC       {ECO:0000305}.
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DR   EMBL; M93015; AAA03036.1; ALT_SEQ; Unassigned_DNA.
DR   PIR; E42573; E42573.
DR   AlphaFoldDB; P29918; -.
DR   SMR; P29918; -.
DR   TCDB; 3.D.1.2.1; the h(+) or na(+)-translocating nadh dehydrogenase (ndh) family.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR   GO; GO:0005506; F:iron ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0008137; F:NADH dehydrogenase (ubiquinone) activity; IEA:InterPro.
DR   GO; GO:0048038; F:quinone binding; IEA:UniProtKB-KW.
DR   HAMAP; MF_01356; NDH1_NuoB; 1.
DR   InterPro; IPR006137; NADH_UbQ_OxRdtase-like_20kDa.
DR   InterPro; IPR006138; NADH_UQ_OxRdtase_20Kd_su.
DR   Pfam; PF01058; Oxidored_q6; 1.
DR   TIGRFAMs; TIGR01957; nuoB_fam; 1.
DR   PROSITE; PS01150; COMPLEX1_20K; 1.
PE   3: Inferred from homology;
KW   4Fe-4S; Cell inner membrane; Cell membrane; Iron; Iron-sulfur; Membrane;
KW   Metal-binding; NAD; Quinone; Translocase; Ubiquinone.
FT   CHAIN           1..173
FT                   /note="NADH-quinone oxidoreductase subunit 6"
FT                   /id="PRO_0000118762"
FT   BINDING         53
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255"
FT   BINDING         54
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255"
FT   BINDING         118
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255"
FT   BINDING         148
FT                   /ligand="[4Fe-4S] cluster"
FT                   /ligand_id="ChEBI:CHEBI:49883"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   173 AA;  19117 MW;  587B86578797CAEF CRC64;
     MTGLNTAGAD RDLATAELNR ELQDKGFLLT TTEDIINWAR NGSLHWMTFG LACCAVEMMQ
     TSMPRYDLER FGTAPRASPR QSDLMIVAGT LTNKMAPALR KVYDQMPEPR YVISMGSCAN
     GGGYYHYSYS VVRGCDRIVP VDIYVPGCPP TAEALLYGIL QLQRRASGAP ARW