ID   DOXD_ACIAM              Reviewed;         184 AA.
AC   P97207;
DT   05-SEP-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1997, sequence version 1.
DT   03-AUG-2022, entry version 58.
DE   RecName: Full=Thiosulfate dehydrogenase [quinone] large subunit;
DE            EC=1.8.5.2;
DE   AltName: Full=Thiosulfate:quinone oxidoreductase;
DE            Short=TQO;
GN   Name=doxD;
OS   Acidianus ambivalens (Desulfurolobus ambivalens).
OC   Archaea; Crenarchaeota; Thermoprotei; Sulfolobales; Sulfolobaceae;
OC   Acidianus.
OX   NCBI_TaxID=2283;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=Lei 10 / DSM 3772 / JCM 9191;
RX   PubMed=9023221; DOI=10.1128/jb.179.4.1344-1353.1997;
RA   Purschke W.G., Schmidt C.L., Petersen A., Schafer G.;
RT   "The terminal quinol oxidase of the hyperthermophilic archaeon Acidianus
RT   ambivalens exhibits a novel subunit structure and gene organization.";
RL   J. Bacteriol. 179:1344-1353(1997).
RN   [2]
RP   PROTEIN SEQUENCE, FUNCTION, IDENTIFICATION BY MASS SPECTROMETRY, CATALYTIC
RP   ACTIVITY, ACTIVITY REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, SUBUNIT, AND
RP   SUBCELLULAR LOCATION.
RX   PubMed=15306018; DOI=10.1111/j.1365-2958.2004.04193.x;
RA   Muller F.H., Bandeiras T.M., Urich T., Teixeira M., Gomes C.M., Kletzin A.;
RT   "Coupling of the pathway of sulphur oxidation to dioxygen reduction:
RT   characterization of a novel membrane-bound thiosulphate:quinone
RT   oxidoreductase.";
RL   Mol. Microbiol. 53:1147-1160(2004).
CC   -!- FUNCTION: TQO plays a role in sulfur oxidation and is proposed to
CC       couple sulfur oxidation to dioxygen reduction; caldariellaquinone or
CC       sulfolobus quinone seem to serve to transfer electrons to the electron
CC       transport chain terminal oxidase formed by DoxBCE.
CC       {ECO:0000269|PubMed:15306018}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=6-decylubiquinone + 2 thiosulfate = 6-decylubiquinol +
CC         tetrathionate; Xref=Rhea:RHEA:10936, ChEBI:CHEBI:15226,
CC         ChEBI:CHEBI:33542, ChEBI:CHEBI:52020, ChEBI:CHEBI:52021; EC=1.8.5.2;
CC         Evidence={ECO:0000269|PubMed:15306018};
CC   -!- ACTIVITY REGULATION: Inhibited by sulfite, metabisulfite and dithonite.
CC       {ECO:0000269|PubMed:15306018}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=3.4 mM for thiosulfate (with ferrocyanide as electron acceptor)
CC         {ECO:0000269|PubMed:15306018};
CC         KM=5.87 mM for thiosulfate (with decylubiquinol as electron acceptor)
CC         {ECO:0000269|PubMed:15306018};
CC         Vmax=78 umol/min/mg enzyme with thiosulfate as substrate
CC         {ECO:0000269|PubMed:15306018};
CC         Note=KM values measured using the TQO doxDA complex.;
CC       pH dependence:
CC         Optimum pH is around 5, the pH range of activity varies in tested
CC         buffers. {ECO:0000269|PubMed:15306018};
CC       Temperature dependence:
CC         Increasing activity in the range between 20 and 92 degrees Celsius.
CC         {ECO:0000269|PubMed:15306018};
CC   -!- SUBUNIT: Heterodimer of a large and a small subunit in a 2:2
CC       stoichiometry (Probable). TQO may associate with the terminal oxidase
CC       formed by doxBCE. {ECO:0000269|PubMed:15306018, ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000269|PubMed:15306018};
CC       Multi-pass membrane protein {ECO:0000269|PubMed:15306018}.
CC   -!- CAUTION: The thiosulfate dehydrogenase [quinone] subunits have
CC       originally been described as components of the aa3-type terminal
CC       oxidase. {ECO:0000305|PubMed:9023221}.
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DR   EMBL; Y08730; CAA69986.1; -; Genomic_DNA.
DR   EMBL; Y09614; CAA70827.1; -; Genomic_DNA.
DR   RefSeq; WP_013774923.1; NZ_WHYS01000002.1.
DR   AlphaFoldDB; P97207; -.
DR   TCDB; 3.D.4.9.1; the proton-translocating cytochrome oxidase (cox) superfamily.
DR   GeneID; 42779564; -.
DR   BioCyc; MetaCyc:MON-12419; -.
DR   BRENDA; 1.8.5.2; 86.
DR   GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR   GO; GO:0016020; C:membrane; IDA:UniProtKB.
DR   GO; GO:1990204; C:oxidoreductase complex; IDA:UniProtKB.
DR   GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0070469; C:respirasome; IEA:UniProtKB-KW.
DR   GO; GO:0048038; F:quinone binding; IEA:UniProtKB-KW.
DR   GO; GO:0043831; F:thiosulfate dehydrogenase (quinone) activity; IEA:UniProtKB-EC.
DR   InterPro; IPR007301; DoxD.
DR   Pfam; PF04173; DoxD; 1.
PE   1: Evidence at protein level;
KW   Cell membrane; Direct protein sequencing; Electron transport; Membrane;
KW   Oxidoreductase; Quinone; Respiratory chain; Transmembrane;
KW   Transmembrane helix; Transport.
FT   CHAIN           1..184
FT                   /note="Thiosulfate dehydrogenase [quinone] large subunit"
FT                   /id="PRO_0000418549"
FT   TRANSMEM        21..38
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        86..106
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        109..129
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
FT   TRANSMEM        137..157
FT                   /note="Helical"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   184 AA;  20410 MW;  28FA991107E0F6B5 CRC64;
     MSGKQSEEFK RTEKMTRMEY LFPVRFAVGW MFLDGGLRKA VLKPAKLDPN SASFVGGKLV
     NFLPHAGPFK GLLLMTLENR SLDVTFLTVF SYIEIIAGLF IIIGLLTRLA ALGALAMSVG
     FAPAYWLGST CEDEWQIGAL LTAGSVTLML TAAGRVWGLD YFLYKKLGDR PIANVPILKW
     IKLW