ID   TPX_STRGN               Reviewed;         163 AA.
AC   P42366;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   25-MAY-2022, entry version 104.
DE   RecName: Full=Thiol peroxidase {ECO:0000255|HAMAP-Rule:MF_00269};
DE            Short=Tpx {ECO:0000255|HAMAP-Rule:MF_00269};
DE            EC=1.11.1.24 {ECO:0000255|HAMAP-Rule:MF_00269};
DE   AltName: Full=Peroxiredoxin tpx {ECO:0000255|HAMAP-Rule:MF_00269};
DE            Short=Prx {ECO:0000255|HAMAP-Rule:MF_00269};
DE   AltName: Full=Thioredoxin peroxidase {ECO:0000255|HAMAP-Rule:MF_00269};
DE   AltName: Full=Thioredoxin-dependent peroxiredoxin {ECO:0000255|HAMAP-Rule:MF_00269};
GN   Name=tpx {ECO:0000255|HAMAP-Rule:MF_00269};
OS   Streptococcus gordonii.
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC   Streptococcus.
OX   NCBI_TaxID=1302;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=ATCC 51656 / PK488;
RX   PubMed=7927711; DOI=10.1128/iai.62.10.4469-4480.1994;
RA   Kolenbrander P.E., Andersen R.N., Ganeshkumar N.;
RT   "Nucleotide sequence of the Streptococcus gordonii PK488 coaggregation
RT   adhesin gene, scaA, and ATP-binding cassette.";
RL   Infect. Immun. 62:4469-4480(1994).
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:0000255|HAMAP-Rule:MF_00269}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-
CC         disulfide + an alcohol + H2O; Xref=Rhea:RHEA:62620, Rhea:RHEA-
CC         COMP:10698, Rhea:RHEA-COMP:10700, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:29950, ChEBI:CHEBI:30879, ChEBI:CHEBI:35924,
CC         ChEBI:CHEBI:50058; EC=1.11.1.24; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_00269};
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_00269}.
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 atypical 2-Cys
CC       peroxiredoxin, C(R) is present in the same subunit to form an
CC       intramolecular disulfide. The disulfide is subsequently reduced by
CC       thioredoxin. {ECO:0000255|HAMAP-Rule:MF_00269}.
CC   -!- SIMILARITY: Belongs to the peroxiredoxin family. Tpx subfamily.
CC       {ECO:0000255|HAMAP-Rule:MF_00269}.
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DR   EMBL; L11577; AAA71948.1; -; Genomic_DNA.
DR   PIR; T11552; T11552.
DR   RefSeq; WP_012130838.1; NZ_RJVY01000008.1.
DR   AlphaFoldDB; P42366; -.
DR   SMR; P42366; -.
DR   GeneID; 61441168; -.
DR   OMA; ITQEPNY; -.
DR   OrthoDB; 1738458at2; -.
DR   GO; GO:0008379; F:thioredoxin peroxidase activity; IEA:UniProtKB-UniRule.
DR   CDD; cd03014; PRX_Atyp2cys; 1.
DR   HAMAP; MF_00269; Tpx; 1.
DR   InterPro; IPR013740; Redoxin.
DR   InterPro; IPR036249; Thioredoxin-like_sf.
DR   InterPro; IPR013766; Thioredoxin_domain.
DR   InterPro; IPR002065; TPX.
DR   InterPro; IPR018219; Tpx_CS.
DR   Pfam; PF08534; Redoxin; 1.
DR   SUPFAM; SSF52833; SSF52833; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
DR   PROSITE; PS01265; TPX; 1.
PE   3: Inferred from homology;
KW   Antioxidant; Disulfide bond; Oxidoreductase; Peroxidase;
KW   Redox-active center.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000250"
FT   CHAIN           2..163
FT                   /note="Thiol peroxidase"
FT                   /id="PRO_0000187910"
FT   DOMAIN          16..162
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00269"
FT   ACT_SITE        58
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00269"
FT   DISULFID        58..92
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_00269"
SQ   SEQUENCE   163 AA;  17912 MW;  EE5160A1764C7D74 CRC64;
     MTTFLGNPVT FTGKQLQVGD TAHDFSLTAT DLSKKTLADF AGKKKVLSII PSIDTGVCST
     QTRRFNQELS DLDNTVVITV SVDLPFAQGK WCAAEGIENA VMLSDYFDHS FGRDYAVLIN
     EWHLLARAVL VLDENNTVTY AEYVDNINTE PDYDAAIAAV KNL