ID   THIO_OPHHA              Reviewed;         105 AA.
AC   Q98TX1;
DT   05-MAR-2002, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 3.
DT   25-MAY-2022, entry version 82.
DE   RecName: Full=Thioredoxin;
DE            Short=Trx;
GN   Name=TXN;
OS   Ophiophagus hannah (King cobra) (Naja hannah).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Ophiophagus.
OX   NCBI_TaxID=8665;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Lee W., Liu H., Zhang Y.;
RT   "cDNA sequence of Ophiophagus hannah venom gland thioredoxin protein.";
RL   Submitted (NOV-2000) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Participates in various redox reactions through the
CC       reversible oxidation of its active center dithiol to a disulfide and
CC       catalyzes dithiol-disulfide exchange reactions (By similarity). Plays a
CC       role in the reversible S-nitrosylation of cysteine residues in target
CC       proteins, and thereby contributes to the response to intracellular
CC       nitric oxide. Nitrosylates the active site Cys of CASP3 in response to
CC       nitric oxide (NO), and thereby inhibits caspase-3 activity. Induces the
CC       FOS/JUN AP-1 DNA binding activity in ionizing radiation (IR) cells
CC       through its oxidation/reduction status and stimulates AP-1
CC       transcriptional activity (By similarity). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Nucleus {ECO:0000250|UniProtKB:P10599}. Cytoplasm
CC       {ECO:0000250|UniProtKB:P10599}. Secreted
CC       {ECO:0000250|UniProtKB:P10599}. Note=Shuttles between the nucleus and
CC       nucleolus. {ECO:0000250|UniProtKB:Q811S9}.
CC   -!- PTM: May be nitrosylated on several cysteine residues, depending on the
CC       oxidation state. Nitrosylated Cys-73 may serve as donor for
CC       nitrosylation of target proteins (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the thioredoxin family. {ECO:0000305}.
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DR   EMBL; AF321769; AAK09384.1; -; mRNA.
DR   AlphaFoldDB; Q98TX1; -.
DR   SMR; Q98TX1; -.
DR   TopDownProteomics; Q98TX1; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0015035; F:protein-disulfide reductase activity; IEA:InterPro.
DR   GO; GO:0043388; P:positive regulation of DNA binding; ISS:UniProtKB.
DR   GO; GO:0009314; P:response to radiation; ISS:UniProtKB.
DR   InterPro; IPR005746; Thioredoxin.
DR   InterPro; IPR036249; Thioredoxin-like_sf.
DR   InterPro; IPR017937; Thioredoxin_CS.
DR   InterPro; IPR013766; Thioredoxin_domain.
DR   Pfam; PF00085; Thioredoxin; 1.
DR   PIRSF; PIRSF000077; Thioredoxin; 1.
DR   SUPFAM; SSF52833; SSF52833; 1.
DR   PROSITE; PS00194; THIOREDOXIN_1; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
PE   3: Inferred from homology;
KW   Activator; Cytoplasm; Disulfide bond; Electron transport; Nucleus;
KW   Redox-active center; S-nitrosylation; Secreted; Transcription;
KW   Transcription regulation; Transport.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000250"
FT   CHAIN           2..105
FT                   /note="Thioredoxin"
FT                   /id="PRO_0000120014"
FT   DOMAIN          2..105
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   ACT_SITE        32
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        35
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   SITE            26
FT                   /note="Deprotonates C-terminal active site Cys"
FT                   /evidence="ECO:0000250"
FT   SITE            33
FT                   /note="Contributes to redox potential value"
FT                   /evidence="ECO:0000250"
FT   SITE            34
FT                   /note="Contributes to redox potential value"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         69
FT                   /note="S-nitrosocysteine"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         73
FT                   /note="S-nitrosocysteine"
FT                   /evidence="ECO:0000250"
FT   DISULFID        32..35
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
SQ   SEQUENCE   105 AA;  12003 MW;  DFBE6507D3769F52 CRC64;
     MVKIVGDLTE FRAELSNAGS KLIVVDFSAT WCGPCKMIKP FFHSMVEKYP DVVFIEIDVD
     DAQDVASHCD VKCMPTFQFY KNNEKVHEFS GANKEKLEEA IKKYM