UniProt functional annotation for P0A251



	UniProt functional annotation for P0A251

UniProt codes: P0A251, P19479.

Organism: Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720).

Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Salmonella.

Function: Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides. {ECO:0000269|PubMed:2643600, ECO:0000269|PubMed:8041738}.

Catalytic activity: Reaction=a hydroperoxide + H(+) + NADH = an alcohol + H2O + NAD(+); Xref=Rhea:RHEA:62628, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30879, ChEBI:CHEBI:35924, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945; EC=1.11.1.26; Evidence={ECO:0000269|PubMed:2643600};

Biophysicochemical properties: Kinetic parameters: KM=1.4 uM for H(2)O(2) {ECO:0000269|PubMed:16060667}; Note=kcat is 55.1 sec(-1) with H(2)O(2) as substrate. {ECO:0000269|PubMed:16060667};

Subunit: Homodimer; disulfide-linked, upon oxidation (PubMed:2643600, PubMed:8555198). 5 homodimers assemble to form a ring-like decamer (PubMed:11969410). {ECO:0000269|PubMed:11969410, ECO:0000269|PubMed:2643600, ECO:0000269|PubMed:8555198}.

Subcellular location: Cytoplasm {ECO:0000250|UniProtKB:P0AE08}.

Miscellaneous: The active site is a conserved redox-active cysteine residue, the peroxidatic cysteine (C(P)), which makes the nucleophilic attack on the peroxide substrate. The peroxide oxidizes the C(P)-SH to cysteine sulfenic acid (C(P)-SOH), which then reacts with another cysteine residue, the resolving cysteine (C(R)), to form a disulfide bridge. The disulfide is subsequently reduced by an appropriate electron donor to complete the catalytic cycle. In this typical 2-Cys peroxiredoxin, C(R) is provided by the other dimeric subunit to form an intersubunit disulfide. The disulfide is subsequently reduced by AhpF. {ECO:0000269|PubMed:7592740, ECO:0000305|PubMed:2643600}.

Similarity: Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Salmonella.



Function:		Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides. {ECO:0000269\|PubMed:2643600, ECO:0000269\|PubMed:8041738}.


Catalytic activity:		Reaction=a hydroperoxide + H(+) + NADH = an alcohol + H2O + NAD(+); Xref=Rhea:RHEA:62628, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:30879, ChEBI:CHEBI:35924, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945; EC=1.11.1.26; Evidence={ECO:0000269\|PubMed:2643600};
Biophysicochemical properties:		Kinetic parameters: KM=1.4 uM for H(2)O(2) {ECO:0000269\|PubMed:16060667}; Note=kcat is 55.1 sec(-1) with H(2)O(2) as substrate. {ECO:0000269\|PubMed:16060667};
Subunit:		Homodimer; disulfide-linked, upon oxidation (PubMed:2643600, PubMed:8555198). 5 homodimers assemble to form a ring-like decamer (PubMed:11969410). {ECO:0000269\|PubMed:11969410, ECO:0000269\|PubMed:2643600, ECO:0000269\|PubMed:8555198}.
Subcellular location:		Cytoplasm {ECO:0000250\|UniProtKB:P0AE08}.
Miscellaneous:		The active site is a conserved redox-active cysteine residue, the peroxidatic cysteine (C(P)), which makes the nucleophilic attack on the peroxide substrate. The peroxide oxidizes the C(P)-SH to cysteine sulfenic acid (C(P)-SOH), which then reacts with another cysteine residue, the resolving cysteine (C(R)), to form a disulfide bridge. The disulfide is subsequently reduced by an appropriate electron donor to complete the catalytic cycle. In this typical 2-Cys peroxiredoxin, C(R) is provided by the other dimeric subunit to form an intersubunit disulfide. The disulfide is subsequently reduced by AhpF. {ECO:0000269\|PubMed:7592740, ECO:0000305\|PubMed:2643600}.
Similarity:		Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily. {ECO:0000305}.