ID   PRXQ_GENTR              Reviewed;         217 AA.
AC   Q75SY5;
DT   01-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   25-MAY-2022, entry version 71.
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=AFP1;
OS   Gentiana triflora (Clustered gentian).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   asterids; lamiids; Gentianales; Gentianaceae; Gentianeae; Gentianinae;
OC   Gentiana.
OX   NCBI_TaxID=55190;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], TISSUE SPECIFICITY, AND INDUCTION.
RX   PubMed=15840643; DOI=10.1093/pcp/pci109;
RA   Kiba A., Nishihara M., Tsukatani N., Nakatsuka T., Kato Y., Yamamura S.;
RT   "A peroxiredoxin Q homolog from gentians is involved in both resistance
RT   against fungal disease and oxidative stress.";
RL   Plant Cell Physiol. 46:1007-1015(2005).
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 (By similarity). Involved in both resistance
CC       against fungal disease and oxidative stress (PubMed:15840643).
CC       {ECO:0000250|UniProtKB:Q9LU86, ECO:0000269|PubMed:15840643}.
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   -!- TISSUE SPECIFICITY: Expressed in the leaves, roots and stems.
CC       {ECO:0000269|PubMed:15840643}.
CC   -!- INDUCTION: By salicylic acid (SA). {ECO:0000269|PubMed:15840643}.
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; AB128915; BAD04985.1; -; mRNA.
DR   AlphaFoldDB; Q75SY5; -.
DR   SMR; Q75SY5; -.
DR   PeroxiBase; 4305; GtrPrxQ.
DR   PRIDE; Q75SY5; -.
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..65
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000255"
FT   CHAIN           66..217
FT                   /note="Peroxiredoxin Q, chloroplastic"
FT                   /id="PRO_0000285110"
FT   DOMAIN          70..217
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   ACT_SITE        112
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000250|UniProtKB:P0AE52"
FT   DISULFID        112..117
FT                   /note="Redox-active"
FT                   /evidence="ECO:0000250|UniProtKB:P0AE52"
SQ   SEQUENCE   217 AA;  23928 MW;  4CCD58BC067E09C8 CRC64;
     MAAICLPVAK HSFPSLLNTQ TPKPLFSQNL HTIPLSSQSQ ICGLKFLISS PSSLPPPPSY
     SARISVFAKV SKGSVPPQFT LKDQDGKNVS LTEFKGKPVV VYFYPADETP GCTKQACAFR
     DSYEKFKKAG AEVIGISGDD PSSHKAFAKK YRLPYTLLSD EGNKIRREWG VPADLFGTLP
     GRQTYVLDKN GTVQLIYNNQ FQPEKHIDET LKFLQSA