ID   1CPX_DIRIM              Reviewed;         235 AA.
AC   O17433; Q9U5A1;
DT   01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT   30-AUG-2017, sequence version 2.
DT   25-MAY-2022, entry version 91.
DE   RecName: Full=1-Cys peroxiredoxin;
DE            EC=1.11.1.- {ECO:0000269|PubMed:10726990};
DE   AltName: Full=1-CysPxn;
DE   AltName: Full=Thioredoxin peroxidase;
OS   Dirofilaria immitis (Canine heartworm).
OC   Eukaryota; Metazoa; Ecdysozoa; Nematoda; Chromadorea; Rhabditida;
OC   Spirurina; Spiruromorpha; Filarioidea; Onchocercidae; Dirofilaria.
OX   NCBI_TaxID=6287;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, CATALYTIC ACTIVITY, AND
RP   BIOPHYSICOCHEMICAL PROPERTIES.
RX   PubMed=10726990; DOI=10.1007/s004360050032;
RA   Chandrashekar R., Tsuji N., Morales T.H., Carmody A.B., Ozols V.O.,
RA   Welton J., Tang L.;
RT   "Removal of hydrogen peroxide by a 1-cysteine peroxiredoxin enzyme of the
RT   filarial parasite Dirofilaria immitis.";
RL   Parasitol. Res. 86:200-206(2000).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   McGonigle S., James E.R.;
RT   "1-Cys peroxidoxin from Dirofilaria immitis.";
RL   Submitted (SEP-1997) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Thiol-specific peroxidase that catalyzes the reduction of
CC       hydrogen peroxide and organic hydroperoxides to water and alcohols,
CC       respectively. Plays a role in cell protection against oxidative stress
CC       by detoxifying peroxides. {ECO:0000269|PubMed:10726990}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[protein]-dithiol + a hydroperoxide = [protein]-disulfide + an
CC         alcohol + H2O; Xref=Rhea:RHEA:10008, Rhea:RHEA-COMP:10593, Rhea:RHEA-
CC         COMP:10594, ChEBI:CHEBI:15377, ChEBI:CHEBI:29950, ChEBI:CHEBI:30879,
CC         ChEBI:CHEBI:35924, ChEBI:CHEBI:50058;
CC         Evidence={ECO:0000269|PubMed:10726990};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=16.28 mM for H(2)O(2) {ECO:0000269|PubMed:10726990};
CC         Vmax=16 umol/min/mg enzyme {ECO:0000269|PubMed:10726990};
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250}.
CC   -!- MISCELLANEOUS: The active site is a conserved redox-active cysteine
CC       residue, the peroxidatic cysteine (C(P)), which makes the nucleophilic
CC       attack on the peroxide substrate. The peroxide oxidizes the C(P)-SH to
CC       cysteine sulfenic acid (C(P)-SOH), which then reacts with another
CC       cysteine residue, the resolving cysteine (C(R)), to form a disulfide
CC       bridge. The disulfide is subsequently reduced by an appropriate
CC       electron donor to complete the catalytic cycle. In this 1-Cys
CC       peroxiredoxin, no C(R) is present and C(P) instead forms a disulfide
CC       with a cysteine from another protein or with a small thiol molecule.
CC       {ECO:0000250|UniProtKB:P34227}.
CC   -!- SIMILARITY: Belongs to the peroxiredoxin family. Prx6 subfamily.
CC       {ECO:0000305}.
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DR   EMBL; AF045164; AAF21097.1; -; mRNA.
DR   EMBL; AF027387; AAB83998.1; -; mRNA.
DR   AlphaFoldDB; O17433; -.
DR   SMR; O17433; -.
DR   PeroxiBase; 4935; Di1CysPrx.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0008379; F:thioredoxin peroxidase activity; IEA:InterPro.
DR   CDD; cd03016; PRX_1cys; 1.
DR   InterPro; IPR000866; AhpC/TSA.
DR   InterPro; IPR024706; Peroxiredoxin_AhpC-typ.
DR   InterPro; IPR019479; Peroxiredoxin_C.
DR   InterPro; IPR045020; PRX_1cys.
DR   InterPro; IPR036249; Thioredoxin-like_sf.
DR   InterPro; IPR013766; Thioredoxin_domain.
DR   Pfam; PF10417; 1-cysPrx_C; 1.
DR   Pfam; PF00578; AhpC-TSA; 1.
DR   PIRSF; PIRSF000239; AHPC; 1.
DR   SUPFAM; SSF52833; SSF52833; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
PE   1: Evidence at protein level;
KW   Antioxidant; Cytoplasm; Oxidoreductase; Peroxidase; Redox-active center.
FT   CHAIN           1..235
FT                   /note="1-Cys peroxiredoxin"
FT                   /id="PRO_0000135106"
FT   DOMAIN          5..179
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   ACT_SITE        49
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        49
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000250|UniProtKB:P30041"
FT   CONFLICT        64
FT                   /note="K -> N (in Ref. 2; AAB83998)"
FT   CONFLICT        193
FT                   /note="G -> D (in Ref. 2; AAB83998)"
SQ   SEQUENCE   235 AA;  26298 MW;  D177468FA6E47576 CRC64;
     MTKGILLGDK FPDFRAETNE GFIPSFYDWI GKDSWAILFS HPRDFTPVCT TELARLVQLA
     PEFKKRNVKL IGLSCDSAES HRKWVDDIMA VCKMKCNDGD TCCSGNKLPF PIIADENRFL
     ATELGMMDPD ERDENGNALT ARCVFIIGPE KTLKLSILYP ATTGRNFDEI LRVVDSLQLT
     AVKLVATPVD WKGGDDCVVL PTIDDTEAKK LFGEKINTIE LPSGKHYLRM VAHPK