| Category | Details | Quantitative data | Key sources (year; URL) | Notes |
|---|---|---:|---|---|
| Verified target identity | **UniProt Q88M05**; gene **aroA**; ordered locus **PP_1770**; organism **Pseudomonas putida KT2440** | — | Molina-Henares et al. 2009; https://doi.org/10.1111/j.1751-7915.2008.00062.x (pqac-00000000) | Literature for PP1770 in KT2440 exists, but direct biochemical characterization of Q88M05 in the retrieved sources is limited. |
| Core enzymatic function | **3-phosphoshikimate 1-carboxyvinyltransferase / 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS; EC 2.5.1.19)** catalyzes **shikimate-3-phosphate (S3P) + phosphoenolpyruvate (PEP) → 5-enolpyruvylshikimate-3-phosphate (EPSP) + inorganic phosphate** | Reaction stoichiometry shown; glyphosate can inhibit by occupying the PEP site | Shende et al. 2024; https://doi.org/10.1039/d3np00037k (pqac-00000001, pqac-00000002) | Current mechanistic understanding places EPSPS as an enolpyruvyl transferase acting through a tetrahedral intermediate; glyphosate is a competitive PEP-site inhibitor. |
| Pathway context | EPSPS performs the **penultimate step of the shikimate pathway**, leading to **chorismate**, the common precursor for **phenylalanine, tyrosine, and tryptophan** biosynthesis | — | Shende et al. 2024; https://doi.org/10.1039/d3np00037k (pqac-00000001); Molina-Henares et al. 2009; https://doi.org/10.1111/j.1751-7915.2008.00062.x (pqac-00000000) | In bacteria this is a **cytosolic metabolic enzyme** in central aromatic amino-acid biosynthesis, inferred from pathway/structural context (pqac-00000002). |
| Annotation inconsistency to flag | PP1770 was reported in one KT2440 pathway source as **“PP1770 or TyrA”** with dual/ambiguous labeling including **“prephenate dehydrogenase, putative/3-phosphoshikimate 1-carboxyvinyltransferase”** | — | Molina-Henares et al. 2009; https://doi.org/10.1111/j.1751-7915.2008.00062.x (pqac-00000000) | This is the main inconsistency that requires caution; the user-supplied UniProt entry specifically identifies Q88M05 as **aroA/EPSPS**, so literature must not be conflated with true **tyrA/prephenate dehydrogenase** studies. |
| P. putida KT2440 engineering relevance | In KT2440 pABA pathway optimization, **aroA** was included among shikimate-pathway genes tuned by combinatorial expression to improve production | Best strain produced **185.4 mg/L pABA**; lowering aroA/aroK/aroQ/aroGD146N expression to native levels caused a **39.9% decrease** in pABA in top strain S12 | Campos-Magaña et al. 2025; https://doi.org/10.1186/s13036-025-00553-5 (pqac-00000012, pqac-00000013, pqac-00000014) | Evidence supports aroA as a practical flux-control point in aromatic-pathway engineering in **P. putida**, although **aroB** was highlighted as the stronger bottleneck in that study. |
| Recent EPSPS developments (general) | Directed evolution platforms are being used to obtain EPSPS variants with both catalytic competence and glyphosate tolerance | One evolved EPSPS variant reached **Ki ≈ 1 mM** for glyphosate and **~2.5-fold improved enzymatic efficiency** versus the starting enzyme | Reed et al. 2024; https://doi.org/10.1073/pnas.2317027121 (pqac-00000004) | This is not P. putida-specific, but it is highly relevant to modern functional interpretation and real-world use of EPSPS enzymes. |
| Recent mechanistic expansion (general) | A 2024 study showed **MurA** can also catalyze **S3P + PEP → EPSP + Pi** in bryophytes, revealing an alternative route to EPSP formation | MurA activity was **~100-fold lower** than EPSPS; MurA activity on S3P/PEP was **~8-fold higher** than on its canonical substrate pair | Caygill et al. 2024; https://doi.org/10.1073/pnas.2412997121 (pqac-00000006, pqac-00000009) | Important for interpreting glyphosate tolerance biology broadly; not evidence that KT2440 uses MurA for this role. |
| Glyphosate resistance relevance | In bacteria, resistance can arise through **target-site aroA mutations**, **EPSPS overproduction/gene amplification**, **transport/efflux changes**, or **glyphosate degradation/detoxification** | Example selection range for Salmonella target-site mutants: **0.35–2 g/L glyphosate** | Hertel et al. 2021; https://doi.org/10.1111/1462-2920.15534 (pqac-00000015, pqac-00000016, pqac-00000018, pqac-00000021) | These mechanisms frame how aroA function is exploited or bypassed under herbicide pressure. |


*Table: This table summarizes the verified identity, biochemical function, pathway role, annotation caveats, and applied relevance of the target protein UniProt Q88M05 / aroA / PP_1770 from Pseudomonas putida KT2440. It also includes recent quantitative findings useful for interpreting EPSPS function and engineering significance.*