ID   BAS1_SPIOL              Reviewed;         265 AA.
AC   O24364;
DT   15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 101.
DE   RecName: Full=2-Cys peroxiredoxin BAS1, chloroplastic;
DE            EC=1.11.1.24 {ECO:0000250|UniProtKB:Q96291};
DE   AltName: Full=Thiol-specific antioxidant protein;
DE   AltName: Full=Thioredoxin-dependent peroxiredoxin BAS1 {ECO:0000305};
DE   Flags: Precursor;
GN   Name=BAS1;
OS   Spinacia oleracea (Spinach).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   Caryophyllales; Chenopodiaceae; Chenopodioideae; Anserineae; Spinacia.
OX   NCBI_TaxID=3562;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Leaf;
RX   PubMed=8790288; DOI=10.1007/bf00042228;
RA   Baier M., Dietz K.-J.;
RT   "Primary structure and expression of plant homologues of animal and fungal
RT   thioredoxin-dependent peroxide reductases and bacterial alkyl hydroperoxide
RT   reductases.";
RL   Plant Mol. Biol. 31:553-564(1996).
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. May be an antioxidant enzyme particularly in
CC       the developing shoot and photosynthesizing leaf.
CC       {ECO:0000250|UniProtKB:Q96291}.
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:Q96291};
CC   -!- SUBUNIT: Homodimer; disulfide-linked, upon oxidation.
CC       {ECO:0000250|UniProtKB:Q06830}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast
CC       {ECO:0000250|UniProtKB:Q96291}.
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 typical 2-Cys
CC       peroxiredoxin, C(R) is provided by the other dimeric subunit to form an
CC       intersubunit disulfide. The disulfide is subsequently reduced by
CC       thioredoxin. {ECO:0000250|UniProtKB:Q96291}.
CC   -!- SIMILARITY: Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily.
CC       {ECO:0000305}.
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DR   EMBL; X94219; CAA63910.1; -; mRNA.
DR   PIR; T09211; T09211.
DR   AlphaFoldDB; O24364; -.
DR   SMR; O24364; -.
DR   IntAct; O24364; 1.
DR   PeroxiBase; 4408; So2CysPrx.
DR   GO; GO:0009507; C:chloroplast; 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; IPR019479; Peroxiredoxin_C.
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   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; Transit peptide.
FT   TRANSIT         1..65
FT                   /note="Chloroplast"
FT                   /evidence="ECO:0000250"
FT   CHAIN           66..265
FT                   /note="2-Cys peroxiredoxin BAS1, chloroplastic"
FT                   /id="PRO_0000023786"
FT   DOMAIN          73..232
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   ACT_SITE        119
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000250|UniProtKB:Q06830"
FT   DISULFID        119
FT                   /note="Interchain (with C-240); in linked form"
FT                   /evidence="ECO:0000250|UniProtKB:Q06830"
FT   DISULFID        240
FT                   /note="Interchain (with C-119); in linked form"
FT                   /evidence="ECO:0000250|UniProtKB:Q06830"
SQ   SEQUENCE   265 AA;  28896 MW;  11F479093C2F573B CRC64;
     MACVASSTTL ISSPSSRVFP AKSSLSSPSV SFLRTLSSPS ASASLRSGFA RRSSLSSTSR
     RSFAVKAQAD DLPLVGNKAP DFEAEAVFDQ EFIKVKLSDY IGKKYVILFF YPLDFTFVCP
     TEITAFSDRH SEFEKLNTEV LGVSVDSVFS HLAWVQTDRK SGGLGDLNYP LISDVTKSIS
     KSFGVLIHDQ GIALRGLFII DKEGVIQHST INNLGIGRSV DETMRTLQAL QYTGNPDEVC
     PAGWKPGEKS MKPDPKLSKE YFSAI