ID   Y755_SYNY3              Reviewed;         200 AA.
AC   Q55624;
DT   15-JUL-1998, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 127.
DE   RecName: Full=Putative peroxiredoxin sll0755;
DE            EC=1.11.1.24 {ECO:0000250|UniProtKB:P0A251};
DE   AltName: Full=Thioredoxin reductase;
GN   OrderedLocusNames=sll0755;
OS   Synechocystis sp. (strain PCC 6803 / Kazusa).
OC   Bacteria; Cyanobacteria; Synechococcales; Merismopediaceae; Synechocystis;
OC   unclassified Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27184 / PCC 6803 / N-1;
RX   PubMed=8590279; DOI=10.1093/dnares/2.4.153;
RA   Kaneko T., Tanaka A., Sato S., Kotani H., Sazuka T., Miyajima N.,
RA   Sugiura M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. I. Sequence features in the 1 Mb region
RT   from map positions 64% to 92% of the genome.";
RL   DNA Res. 2:153-166(1995).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(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. {ECO:0000250|UniProtKB:P0A251}.
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:P0A251};
CC   -!- SUBUNIT: Homodimer; disulfide-linked, upon oxidation.
CC       {ECO:0000250|UniProtKB:P0A251}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P0AE08}.
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. {ECO:0000250|UniProtKB:P0A251}.
CC   -!- SIMILARITY: Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily.
CC       {ECO:0000305}.
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DR   EMBL; BA000022; BAA10136.1; -; Genomic_DNA.
DR   PIR; S76284; S76284.
DR   AlphaFoldDB; Q55624; -.
DR   SMR; Q55624; -.
DR   IntAct; Q55624; 2.
DR   STRING; 1148.1001510; -.
DR   PeroxiBase; 4412; SYspAhpC.
DR   PaxDb; Q55624; -.
DR   EnsemblBacteria; BAA10136; BAA10136; BAA10136.
DR   KEGG; syn:sll0755; -.
DR   eggNOG; COG0450; Bacteria.
DR   InParanoid; Q55624; -.
DR   OMA; FWYPKDF; -.
DR   PhylomeDB; Q55624; -.
DR   BRENDA; 1.11.1.24; 6192.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0005829; C:cytosol; IBA:GO_Central.
DR   GO; GO:0004601; F:peroxidase activity; IEA:UniProtKB-KW.
DR   GO; GO:0051920; F:peroxiredoxin activity; IEA:UniProtKB-EC.
DR   GO; GO:0045454; P:cell redox homeostasis; IBA:GO_Central.
DR   InterPro; IPR000866; AhpC/TSA.
DR   InterPro; IPR024706; Peroxiredoxin_AhpC-typ.
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   PIRSF; PIRSF000239; AHPC; 1.
DR   SUPFAM; SSF52833; SSF52833; 1.
DR   PROSITE; PS51352; THIOREDOXIN_2; 1.
PE   3: Inferred from homology;
KW   Antioxidant; Cytoplasm; Disulfide bond; Oxidoreductase; Peroxidase;
KW   Redox-active center; Reference proteome.
FT   CHAIN           1..200
FT                   /note="Putative peroxiredoxin sll0755"
FT                   /id="PRO_0000135150"
FT   DOMAIN          5..163
FT                   /note="Thioredoxin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00691"
FT   ACT_SITE        50
FT                   /note="Cysteine sulfenic acid (-SOH) intermediate"
FT                   /evidence="ECO:0000250|UniProtKB:P0A251"
FT   DISULFID        50
FT                   /note="Interchain (with C-172); in linked form"
FT                   /evidence="ECO:0000250|UniProtKB:P0A251"
FT   DISULFID        172
FT                   /note="Interchain (with C-50); in linked form"
FT                   /evidence="ECO:0000250|UniProtKB:P0A251"
SQ   SEQUENCE   200 AA;  22510 MW;  89EBFC9123CAD30A CRC64;
     MTEVLRVGQP APDFTATAIV DQSFQTVKLS TYRGKYLVLF FYPLDFTFVC PTEIIAFSDR
     HSEFTALDTE VVGISVDSEF SHLAWIQTER KMGGIGNINY PLVSDLKKEI SQAYNVLEPD
     AGIALRGLFI IDREGILQYA TVNNLSFGRS VDETLRVLKA IRHVQSHPNE VCPVDWQEGD
     KTMIPDPEKA KTYFETVAEP