ID   TRXB_SPIBA              Reviewed;         305 AA.
AC   Q8T6Z1;
DT   10-OCT-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2002, sequence version 1.
DT   03-AUG-2022, entry version 68.
DE   RecName: Full=Thioredoxin reductase;
DE            EC=1.8.1.9;
DE   AltName: Full=L-TrxR;
DE   Flags: Fragment;
GN   Name=TRXB;
OS   Spironucleus barkhanus.
OC   Eukaryota; Metamonada; Diplomonadida; Hexamitidae; Hexamitinae;
OC   Spironucleus.
OX   NCBI_TaxID=103874;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=12379950; DOI=10.1016/s1471-4922(02)02293-6;
RA   Hirt R.P., Mueller S., Embley T.M., Coombs G.H.;
RT   "The diversity and evolution of thioredoxin reductase: new perspectives.";
RL   Trends Parasitol. 18:302-308(2002).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-dithiol + NADP(+) = [thioredoxin]-disulfide +
CC         H(+) + NADPH; Xref=Rhea:RHEA:20345, Rhea:RHEA-COMP:10698, Rhea:RHEA-
CC         COMP:10700, ChEBI:CHEBI:15378, ChEBI:CHEBI:29950, ChEBI:CHEBI:50058,
CC         ChEBI:CHEBI:57783, ChEBI:CHEBI:58349; EC=1.8.1.9;
CC   -!- COFACTOR:
CC       Name=FAD; Xref=ChEBI:CHEBI:57692;
CC         Evidence={ECO:0000250|UniProtKB:P0A9P4};
CC       Note=Binds 1 FAD per subunit. {ECO:0000250|UniProtKB:P0A9P4};
CC   -!- SUBUNIT: Homodimer. {ECO:0000250|UniProtKB:P0A9P4}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250}.
CC   -!- MISCELLANEOUS: The active site is a redox-active disulfide bond.
CC   -!- SIMILARITY: Belongs to the class-II pyridine nucleotide-disulfide
CC       oxidoreductase family. {ECO:0000305}.
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DR   EMBL; AF394238; AAM00424.1; -; mRNA.
DR   AlphaFoldDB; Q8T6Z1; -.
DR   SMR; Q8T6Z1; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0004791; F:thioredoxin-disulfide reductase activity; IEA:UniProtKB-EC.
DR   GO; GO:0019430; P:removal of superoxide radicals; IEA:InterPro.
DR   Gene3D; 3.50.50.60; -; 2.
DR   InterPro; IPR036188; FAD/NAD-bd_sf.
DR   InterPro; IPR023753; FAD/NAD-binding_dom.
DR   InterPro; IPR008255; Pyr_nucl-diS_OxRdtase_2_AS.
DR   InterPro; IPR005982; Thioredox_Rdtase.
DR   Pfam; PF07992; Pyr_redox_2; 1.
DR   SUPFAM; SSF51905; SSF51905; 1.
DR   TIGRFAMs; TIGR01292; TRX_reduct; 1.
DR   PROSITE; PS00573; PYRIDINE_REDOX_2; 1.
PE   2: Evidence at transcript level;
KW   Cytoplasm; Disulfide bond; FAD; Flavoprotein; NADP; Oxidoreductase;
KW   Redox-active center.
FT   CHAIN           <1..305
FT                   /note="Thioredoxin reductase"
FT                   /id="PRO_0000166760"
FT   BINDING         28..35
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:P0A9P4"
FT   BINDING         272..281
FT                   /ligand="FAD"
FT                   /ligand_id="ChEBI:CHEBI:57692"
FT                   /evidence="ECO:0000250|UniProtKB:P0A9P4"
FT   DISULFID        129..132
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000250|UniProtKB:P0A9P4"
FT   NON_TER         1
SQ   SEQUENCE   305 AA;  32907 MW;  7C4DCE73A0626A20 CRC64;
     LVIVGGGPGG LAAAIYAGRA GLTPVIFLGI ETSSQLMTTT EVENYPGFKT IQGPDLVQNQ
     VDQAEHCGAQ LFYEDVTKID ATARPFKITH GYENEIMTCD ALIFATGSTA QRLDVIGEKQ
     FWQKGVSACA VCDSMMAKNK DTVVVGGGDV ACEEASYLSN IASKVYLILR RDAFRASAAM
     VQRVKSNPKI EIIYNSAVQE IKGETRVNQI LVKNLKSGDI TPLKVEALFW CIGHTPQTRL
     LKGQVKMSEN GYILVENQTQ YTNVPGIFAA GDCCDWIYRQ AIVAAGSGCK AALDAERWLA
     SNGGH