Q9LU86 · PRXQ_ARATH
- ProteinPeroxiredoxin Q, chloroplastic
- GenePRXQ
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids216 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
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. Involved in the photosystem II protection against hydrogen peroxide.
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 atypical 2-Cys peroxiredoxin, C(R) is present in the same subunit to form an intramolecular disulfide. The disulfide is subsequently reduced by thioredoxin.
Catalytic activity
- [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O
RHEA-COMP:10698 CHEBI:29950 Position: nCHEBI:29950 Position: n+3+ CHEBI:35924 = RHEA-COMP:10700 CHEBI:50058 Position: n/n+3+ CHEBI:30879 + CHEBI:15377
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
254 μM | H2O2 | |||||
1.09 μM | thioredoxin |
kcat is 4.5 sec-1 for H2O2. kcat is 2.75 sec-1 for thioredoxin.
pH Dependence
Optimum pH is 8.0.
Temperature Dependence
Optimum temperature is 40 degrees Celsius.
Features
Showing features for active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Active site | 111 | Cysteine sulfenic acid (-SOH) intermediate | ||||
Sequence: C |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | chloroplast thylakoid lumen | |
Cellular Component | chloroplast thylakoid membrane | |
Cellular Component | cytoplasm | |
Molecular Function | thioredoxin peroxidase activity | |
Biological Process | cell redox homeostasis | |
Biological Process | cellular response to oxidative stress |
Keywords
- Molecular function
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended namePeroxiredoxin Q, chloroplastic
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis
Accessions
- Primary accessionQ9LU86
Proteomes
Organism-specific databases
Genome annotation databases
Subcellular Location
PTM/Processing
Features
Showing features for transit peptide, chain, disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transit peptide | ?-67 | Thylakoid | ||||
Sequence: MAASSSSFTLCNHTTLRTLPLRKTLVTKTQFSVPTKSSESNFFGSTLTHSSYISPVSSSSLKGLIFA | ||||||
Transit peptide | 1-? | Chloroplast | ||||
Chain | PRO_0000285109 | 68-216 | Peroxiredoxin Q, chloroplastic | |||
Sequence: KVNKGQAAPDFTLKDQNGKPVSLKKYKGKPVVLYFYPADETPGCTKQACAFRDSYEKFKKAGAEVIGISGDDSASHKAFASKYKLPYTLLSDEGNKVRKDWGVPGDLFGALPGRQTYVLDKNGVVQLIYNNQFQPEKHIDETLKFLKAA | ||||||
Disulfide bond | 111↔116 | Redox-active | ||||
Sequence: CTKQAC |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Expressed in all tissues at the exception of roots.
Induction
Highly induced by oxidative stress. Down-regulated by salt stress and by ascorbate.
Gene expression databases
Interaction
Subunit
Monomer; Interacts with the plastidial thioredoxin CDSP32.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
XENO | Q9LU86 | P07591 | 2 | EBI-540311, EBI-537449 | |
XENO | Q9LU86 | trxA P0AA25 | 2 | EBI-540311, EBI-368542 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 69-216 | Thioredoxin | ||||
Sequence: VNKGQAAPDFTLKDQNGKPVSLKKYKGKPVVLYFYPADETPGCTKQACAFRDSYEKFKKAGAEVIGISGDDSASHKAFASKYKLPYTLLSDEGNKVRKDWGVPGDLFGALPGRQTYVLDKNGVVQLIYNNQFQPEKHIDETLKFLKAA |
Sequence similarities
Belongs to the peroxiredoxin family. BCP/PrxQ subfamily.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
This entry describes 1 isoforms produced by Alternative splicing. A number of isoforms are produced. According to EST sequences.
Q9LU86-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length216
- Mass (Da)23,678
- Last updated2000-10-01 v1
- Checksum5DACF66AC059D10E
Computationally mapped potential isoform sequences
There are 2 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
F4JBC9 | F4JBC9_ARATH | PRXQ | 217 | ||
A0A1I9LR27 | A0A1I9LR27_ARATH | PRXQ | 154 |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AB023041 EMBL· GenBank· DDBJ | BAB01069.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CP002686 EMBL· GenBank· DDBJ | AEE77109.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY048264 EMBL· GenBank· DDBJ | AAK82526.1 EMBL· GenBank· DDBJ | mRNA | ||
AY072626 EMBL· GenBank· DDBJ | AAL62017.1 EMBL· GenBank· DDBJ | mRNA |