ID   NUOK2_SYMTH             Reviewed;         107 AA.
AC   Q67KP3;
DT   15-DEC-2009, integrated into UniProtKB/Swiss-Prot.
DT   11-OCT-2004, sequence version 1.
DT   25-MAY-2022, entry version 97.
DE   RecName: Full=NADH-quinone oxidoreductase subunit K 2 {ECO:0000255|HAMAP-Rule:MF_01456};
DE            EC=7.1.1.- {ECO:0000255|HAMAP-Rule:MF_01456};
DE   AltName: Full=NADH dehydrogenase I subunit K 2 {ECO:0000255|HAMAP-Rule:MF_01456};
DE   AltName: Full=NDH-1 subunit K 2 {ECO:0000255|HAMAP-Rule:MF_01456};
GN   Name=nuoK2 {ECO:0000255|HAMAP-Rule:MF_01456}; OrderedLocusNames=STH2770;
OS   Symbiobacterium thermophilum (strain T / IAM 14863).
OC   Bacteria; Firmicutes; Clostridia; Eubacteriales; Symbiobacteriaceae;
OC   Symbiobacterium.
OX   NCBI_TaxID=292459;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=T / IAM 14863;
RX   PubMed=15383646; DOI=10.1093/nar/gkh830;
RA   Ueda K., Yamashita A., Ishikawa J., Shimada M., Watsuji T., Morimura K.,
RA   Ikeda H., Hattori M., Beppu T.;
RT   "Genome sequence of Symbiobacterium thermophilum, an uncultivable bacterium
RT   that depends on microbial commensalism.";
RL   Nucleic Acids Res. 32:4937-4944(2004).
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 a
CC       menaquinone. 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. {ECO:0000255|HAMAP-Rule:MF_01456}.
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         Evidence={ECO:0000255|HAMAP-Rule:MF_01456};
CC   -!- SUBUNIT: NDH-1 is composed of 14 different subunits. Subunits NuoA, H,
CC       J, K, L, M, N constitute the membrane sector of the complex.
CC       {ECO:0000255|HAMAP-Rule:MF_01456}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000255|HAMAP-Rule:MF_01456};
CC       Multi-pass membrane protein {ECO:0000255|HAMAP-Rule:MF_01456}.
CC   -!- SIMILARITY: Belongs to the complex I subunit 4L family.
CC       {ECO:0000255|HAMAP-Rule:MF_01456}.
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DR   EMBL; AP006840; BAD41755.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q67KP3; -.
DR   SMR; Q67KP3; -.
DR   STRING; 292459.STH2770; -.
DR   EnsemblBacteria; BAD41755; BAD41755; STH2770.
DR   KEGG; sth:STH2770; -.
DR   eggNOG; COG0713; Bacteria.
DR   HOGENOM; CLU_144724_1_1_9; -.
DR   OMA; NFVAFSY; -.
DR   OrthoDB; 2081663at2; -.
DR   Proteomes; UP000000417; Chromosome.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0050136; F:NADH dehydrogenase (quinone) activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0048038; F:quinone binding; IEA:UniProtKB-KW.
DR   GO; GO:0042773; P:ATP synthesis coupled electron transport; IEA:InterPro.
DR   HAMAP; MF_01456; NDH1_NuoK; 1.
DR   InterPro; IPR001133; NADH_UbQ_OxRdtase_chain4L/K.
DR   InterPro; IPR039428; NUOK/Mnh_C1-like.
DR   PANTHER; PTHR11434; PTHR11434; 1.
DR   Pfam; PF00420; Oxidored_q2; 1.
PE   3: Inferred from homology;
KW   Cell membrane; Membrane; NAD; Quinone; Reference proteome; Translocase;
KW   Transmembrane; Transmembrane helix; Transport.
FT   CHAIN           1..107
FT                   /note="NADH-quinone oxidoreductase subunit K 2"
FT                   /id="PRO_0000390259"
FT   TRANSMEM        3..23
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01456"
FT   TRANSMEM        30..50
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01456"
FT   TRANSMEM        67..87
FT                   /note="Helical"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01456"
SQ   SEQUENCE   107 AA;  11700 MW;  089AD5B260E223AB CRC64;
     MELPIYYPLG LGALLFGLGL WGALTQKNAV RILMFIEIML NGVNLNLITF SRYYWQTSPE
     MAARAPILTL FVMTVAAAEA SVGLAIILAM VRNRGVVEVD KATLLKG