| Item | Key finding | Organism context (KT2440 vs general) | Best supporting citation IDs | Publication info (authors, year, title, DOI/URL, month/year) |
|---|---|---|---|---|
| Identity | PP_1084 from *Pseudomonas putida* KT2440 is a 21 kDa AhpC/Tsa-family peroxiredoxin (typical 2-Cys Prx); this matches the UniProt Q88NW9 annotation as TsaA/thioredoxin peroxidase rather than an unrelated protein family. | KT2440-specific | (pqac-00000000, pqac-00000001, pqac-00000002) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, Cell Stress and Chaperones, DOI: https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Primary function | PP_1084/PpPrx is a thioredoxin-dependent peroxide-detoxifying enzyme with dual behavior: peroxidase activity plus stress-associated molecular chaperone activity. | KT2440-specific | (pqac-00000000, pqac-00000002, pqac-00000003) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Mechanism | As an AhpC/Prx1 typical 2-Cys peroxiredoxin, the catalytic cycle is inferred to use a peroxidatic cysteine oxidized to sulfenic acid, then an intersubunit disulfide with a resolving cysteine, followed by thioredoxin-dependent reduction. | General AhpC/Prx1 mechanism, applied to PP_1084 family assignment | (pqac-00000005, pqac-00000006, pqac-00000010, pqac-00000012) | Sadowska-Bartosz I & Bartosz G, 2023, *Peroxiredoxin 2: An Important Element of the Antioxidant Defense of the Erythrocyte*, https://doi.org/10.3390/antiox12051012, Apr 2023; Guevara-Flores A et al., 2024, *A Physiological Approach to Explore How Thioredoxin–Glutathione Reductase (TGR) and Peroxiredoxin (Prx) Eliminate H2O2 in Cysticerci of Taenia*, https://doi.org/10.3390/antiox13040444, Apr 2024; Thapa P et al., 2023, *The Role of Peroxiredoxins in Cancer Development*, https://doi.org/10.3390/biology12050666, Apr 2023 |
| Catalytic residue clues | Sequence analysis of PpPrx found two highly conserved VCP tripeptides associated with catalytic cysteines, supporting classification as a typical 2-Cys peroxiredoxin, although exact PP_1084 residue numbers were not given in the retrieved excerpts. | KT2440-specific sequence feature | (pqac-00000001, pqac-00000002) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Substrates | Direct KT2440 evidence supports activity toward H2O2; by subfamily inference, AhpC/Prx1 enzymes also reduce organic hydroperoxides and can act on peroxynitrite. | H2O2: KT2440-specific; broader substrate range: general AhpC/Prx1 | (pqac-00000001, pqac-00000005, pqac-00000008, pqac-00000011, pqac-00000012) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011; Sadowska-Bartosz I & Bartosz G, 2023, *Peroxiredoxin 2...*, https://doi.org/10.3390/antiox12051012, Apr 2023; Thapa P et al., 2023, *The Role of Peroxiredoxins in Cancer Development*, https://doi.org/10.3390/biology12050666, Apr 2023 |
| Reductant / partner system | Peroxidase activity for PP_1084 was measured with a yeast thioredoxin system, and the authors conclude structural/functional switching is primarily guided by the thioredoxin system; this fits canonical Trx/TrxR/NADPH recycling of AhpC/Prx1 enzymes. | KT2440-specific experimental dependence plus general family mechanism | (pqac-00000000, pqac-00000002, pqac-00000003, pqac-00000005, pqac-00000006) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011; Sadowska-Bartosz I & Bartosz G, 2023, *Peroxiredoxin 2...*, https://doi.org/10.3390/antiox12051012, Apr 2023 |
| Oligomerization | PP_1084/PpPrx self-associates into high-molecular-weight (HMW) complexes and lower-molecular-weight (LMW) species; typical 2-Cys Prxs generally exist as dimers and larger toroid/decamer-like assemblies. | KT2440-specific plus general family context | (pqac-00000000, pqac-00000002, pqac-00000007, pqac-00000011) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011; Thapa P et al., 2023, *The Role of Peroxiredoxins in Cancer Development*, https://doi.org/10.3390/biology12050666, Apr 2023 |
| Chaperone role | In KT2440, HMW PP_1084 complexes have strong molecular chaperone activity, suppressing thermal aggregation of model substrates; oxidative conditions shift the balance toward LMW forms with greater peroxidase activity. | KT2440-specific | (pqac-00000001, pqac-00000002, pqac-00000003, pqac-00000014, pqac-00000017) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Localization | PSORTb prediction places PP_1084/PpPrx in the cytoplasm, consistent with a role in intracellular peroxide detoxification and thioredoxin-linked redox homeostasis. | KT2440-specific prediction | (pqac-00000001, pqac-00000014) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Biological process / pathway | The protein functions in oxidative-stress defense/redox homeostasis, especially detoxification of intracellular peroxides generated during stress; in KT2440 it was isolated among disulfide-bonded proteins after H2O2 or gamma-ray exposure. | KT2440-specific, with family-level redox-homeostasis context | (pqac-00000001, pqac-00000004, pqac-00000014, pqac-00000017) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Activity level nuance | The recombinant KT2440 protein showed detectable but comparatively low H2O2 peroxidase activity versus a yeast thioredoxin peroxidase control, while exhibiting comparatively stronger chaperone activity. | KT2440-specific | (pqac-00000001, pqac-00000003, pqac-00000014) | An BC et al., 2011, *Functional switching of a novel prokaryotic 2-Cys peroxiredoxin (PpPrx) under oxidative stress*, https://doi.org/10.1007/s12192-010-0243-5, May 2011 |
| Recent kinetics/statistics | Recent reviews report typical 2-Cys Prx reaction rates with H2O2 in the ~10^5–10^8 M−1 s−1 range; competing condensation vs hyperoxidation parameters around kd ~2 s−1 and kh ~1×10^4 M−1 s−1; thioredoxin reduction second-order rate ~2.1×10^5 M−1 s−1 with Km ~2–2.7 µM; intracellular concentrations can be ~15–60 µM. These are family-level values, not KT2440-specific measurements. | General current understanding (2023–2024) | (pqac-00000006, pqac-00000010) | Sadowska-Bartosz I & Bartosz G, 2023, *Peroxiredoxin 2...*, https://doi.org/10.3390/antiox12051012, Apr 2023; Guevara-Flores A et al., 2024, *A Physiological Approach to Explore How Thioredoxin–Glutathione Reductase (TGR) and Peroxiredoxin (Prx) Eliminate H2O2 in Cysticerci of Taenia*, https://doi.org/10.3390/antiox13040444, Apr 2024 |
| Hyperoxidation / robustness context | Recent literature distinguishes hyperoxidation-sensitive versus robust typical 2-Cys Prxs by conserved motifs; bacterial AhpC-like enzymes are often more resistant to hyperoxidation than many eukaryotic homologs, supporting durable antioxidant function during repeated oxidative challenge. | General bacterial AhpC/Prx1 context | (pqac-00000005, pqac-00000010) | Sadowska-Bartosz I & Bartosz G, 2023, *Peroxiredoxin 2...*, https://doi.org/10.3390/antiox12051012, Apr 2023; Guevara-Flores A et al., 2024, *A Physiological Approach to Explore How Thioredoxin–Glutathione Reductase (TGR) and Peroxiredoxin (Prx) Eliminate H2O2 in Cysticerci of Taenia*, https://doi.org/10.3390/antiox13040444, Apr 2024 |
| Applications / implementations | No direct applied implementation of PP_1084 itself was found in the retrieved KT2440 literature. However, 2024 bioremediation work in another soil bacterium shows that oxidative-stress programs involving Ahp/peroxiredoxin enzymes are upregulated during aromatic-compound degradation and are relevant to strain robustness and soil-microcosm biodegradation performance; thus PP_1084 likely contributes to the oxidative-stress tolerance valued in *P. putida* as a biotechnological chassis. | KT2440 evidence indirect; application evidence from related bacteria/general Pseudomonas biotechnology context | (pqac-00000013, pqac-00000015, pqac-00000016, pqac-00000018, pqac-00000019) | Rodríguez-Castro L et al., 2024, *The long-chain flavodoxin FldX1 improves the biodegradation of 4-hydroxyphenylacetate and 3-hydroxyphenylacetate and counteracts the oxidative stress associated to aromatic catabolism in Paraburkholderia xenovorans*, https://doi.org/10.1186/s40659-024-00491-4, Apr 2024; Nies SC, 2022, *Engineering Pseudomonas for the production of reduced compounds*, journal/DOI not fully resolved in retrieved metadata, 2022 |


*Table: This table summarizes the main functional annotation evidence for Pseudomonas putida KT2440 tsaA/PP_1084 (UniProt Q88NW9), distinguishing direct KT2440 data from broader AhpC/Prx1 family inference. It is useful for tracing each annotation claim to specific supporting citations and recent mechanistic context.*