ID   PERQ_SUASA              Reviewed;         214 AA.
AC   Q6UBI3;
DT   01-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 84.
DE   RecName: Full=Peroxiredoxin Q, chloroplastic;
DE            EC=1.11.1.24 {ECO:0000250|UniProtKB:Q9LU86};
DE   AltName: Full=Thioredoxin peroxidase;
DE   AltName: Full=Thioredoxin-dependent peroxiredoxin Q {ECO:0000305};
DE   Flags: Precursor;
GN   Name=PRXQ;
OS   Suaeda salsa (Seepweed) (Chenopodium salsum).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Chenopodiaceae; Suaedoideae; Suaeda.
OX   NCBI_TaxID=126914;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND INDUCTION.
RX   AGRICOLA=IND43645556; DOI=10.1016/j.plantsci.2004.05.004;
RA   Guo X.-L., Cao Y.-R., Cao Z.-Y., Zhao Y.-X., Zhang H.;
RT   "Molecular cloning and characterization of a stress-induced peroxiredoxin Q
RT   gene in halophyte Suaeda salsa.";
RL   Plant Sci. 167:969-975(2004).
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:0000250|UniProtKB:Q9LU86}.
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;
CC         Evidence={ECO:0000250|UniProtKB:Q9LU86};
CC   -!- SUBUNIT: Monomer. {ECO:0000250|UniProtKB:Q9LU86}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast thylakoid lumen
CC       {ECO:0000250|UniProtKB:Q9LU86}.
CC   -!- INDUCTION: Up-regulated by NaCl, mannitol, low temperature, H(2)O(2),
CC       methyl viologen, and abscisic acid (ABA). {ECO:0000269|Ref.1}.
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:0000250|UniProtKB:P0AE52}.
CC   -!- SIMILARITY: Belongs to the peroxiredoxin family. BCP/PrxQ subfamily.
CC       {ECO:0000305}.
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DR   EMBL; AY373447; AAQ67661.1; -; mRNA.
DR   AlphaFoldDB; Q6UBI3; -.
DR   SMR; Q6UBI3; -.
DR   PeroxiBase; 4306; SsaPrxQ.
DR   PRIDE; Q6UBI3; -.
DR   GO; GO:0009543; C:chloroplast thylakoid lumen; IEA:UniProtKB-SubCell.
DR   GO; GO:0004601; F:peroxidase activity; IEA:UniProtKB-KW.
DR   GO; GO:0051920; F:peroxiredoxin activity; IEA:UniProtKB-EC.
DR   InterPro; IPR000866; AhpC/TSA.
DR   InterPro; IPR036249; Thioredoxin-like_sf.
DR   InterPro; IPR013766; Thioredoxin_domain.
DR   Pfam; PF00578; AhpC-TSA; 1.
DR   SUPFAM; SSF52833; SSF52833; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
PE   2: Evidence at transcript level;
KW   Antioxidant; Chloroplast; Disulfide bond; Oxidoreductase; Peroxidase;
KW   Plastid; Redox-active center; Thylakoid; Transit peptide.
FT   TRANSIT         1..64
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           65..214
FT                   /note="Peroxiredoxin Q, chloroplastic"
FT                   /id="PRO_0000285113"
FT   DOMAIN          67..214
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   REGION          1..27
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        109
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000250|UniProtKB:P0AE52"
FT   DISULFID        109..114
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000250|UniProtKB:P0AE52"
SQ   SEQUENCE   214 AA;  23589 MW;  83D5F660082AC855 CRC64;
     MATLSLPNHS PTFALPSQTP KPHSSQNLSI ISKSAHSQFC GIKLSHSSSL SPPLYPRSYK
     ASIVAKVSEG SMPPAFTLKD QDGKNVSLSK FKGKPVVVYF YPADETPGCT KQACAFRDSY
     EKFKKAGAEV IGISGDDSSS HKAFKQKYKL PYTLLSDEGN KVRKDWGVPS DLFGALPGRQ
     TYVLDRNGVV RLVYNNQFQP EKHIDETLKF LQSL