| Category | Key points | Best supporting citations (pqac IDs) | URLs / publication dates |
|---|---|---|---|
| Identity | UniProt Q88QS1 corresponds to **trpE / PP_0417** in *Pseudomonas putida* KT2440 and encodes **anthranilate synthase component I** (large/synthase subunit) in tryptophan biosynthesis; KT2440 studies explicitly annotate PP0417 as **TrpE** and show loss of function causes tryptophan auxotrophy. | (pqac-00000001, pqac-00000002) | Molina-Henares et al., *Microbial Biotechnology* (Dec 2009): https://doi.org/10.1111/j.1751-7915.2008.00062.x |
| Reaction | TrpE is the synthase/alpha component of **anthranilate synthase (EC 4.1.3.27)**, catalyzing the **first committed step of L-tryptophan biosynthesis** by converting chorismate to anthranilate in concert with TrpG. Mechanistically, TrpE forms/acts on the aminated chorismate intermediate and supports pyruvate elimination. | (pqac-00000005, pqac-00000007) | Parthasarathy et al., *Frontiers in Molecular Biosciences* (Apr 2018): https://doi.org/10.3389/fmolb.2018.00029; Naz et al., *Microbial Cell Factories* (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z |
| Substrates / products | Canonical glutamine-dependent reaction uses **chorismate** plus ammonia derived from **glutamine**; products are **anthranilate**, **pyruvate**, and **glutamate**. Under some conditions, the alpha subunit can use free ammonia instead of glutamine-derived ammonia. | (pqac-00000005, pqac-00000008) | Parthasarathy et al. (Apr 2018): https://doi.org/10.3389/fmolb.2018.00029; Naz et al. (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z |
| Pathway role | In KT2440, trpE functions at or before **anthranilate formation** in the one-way pathway from chorismate to tryptophan; precursor-feeding experiments showed **trpE mutants are rescued by anthranilate, indole, or tryptophan**, placing TrpE upstream of these intermediates. | (pqac-00000000, pqac-00000002, pqac-00000014) | Molina-Henares et al. (Dec 2009): https://doi.org/10.1111/j.1751-7915.2008.00062.x |
| Complex / partner | TrpE acts with **TrpG** (anthranilate synthase component II / glutamine amidotransferase) as a two-subunit enzyme, commonly organized as **αβ or α2β2** assemblies; TrpG supplies ammonia from glutamine to the TrpE active site. Conserved subunit interfaces are essential for activity. | (pqac-00000005, pqac-00000007, pqac-00000010, pqac-00000011) | Parthasarathy et al. (Apr 2018): https://doi.org/10.3389/fmolb.2018.00029; Naz et al. (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z; Funke et al., *Applied and Environmental Microbiology* (May 2024): https://doi.org/10.1128/aem.00572-24 |
| Regulation | Anthranilate synthase is **feedback-inhibited by L-tryptophan**. Structural analyses place inhibitory residues in/near the chorismate-binding domain and domain interfaces; elevated Trp prevents the conformational state needed for efficient catalysis/ammonia transfer. Feedback-insensitive **trpE** alleles are widely exploited in engineering. | (pqac-00000006, pqac-00000007, pqac-00000008, pqac-00000013) | Niraula et al. (Jan 2025): https://doi.org/10.3390/biotech14010006; Naz et al. (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z; Ramos-Valdovinos & Martínez-Antonio, *Processes* (Nov 2024): https://doi.org/10.3390/pr12112422 |
| Gene organization | In *P. putida* KT2440, **trpE is a monocistronic transcription unit** separate from the **trpGDC** operon; trp genes are split across multiple chromosomal loci, with **trpBA** and **trpI** elsewhere. Engineering literature also notes **trpEG and trpDC are encoded by separate open reading frames** in KT2440. | (pqac-00000000, pqac-00000001, pqac-00000004, pqac-00000014) | Molina-Henares et al. (Dec 2009): https://doi.org/10.1111/j.1751-7915.2008.00062.x; Kuepper et al., *Frontiers in Microbiology* (Nov 2015): https://doi.org/10.3389/fmicb.2015.01310 |
| Localization | TrpE is a **cytosolic enzyme** inferred from its role in soluble primary metabolism and from its bacterial anthranilate synthase family organization; no evidence in the gathered KT2440 sources suggests membrane or extracellular localization. | (pqac-00000005, pqac-00000007) | Parthasarathy et al. (Apr 2018): https://doi.org/10.3389/fmolb.2018.00029; Naz et al. (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z |
| Phenotypes | A **mini-Tn5 insertion in trpE** produced a **tryptophan auxotroph** in KT2440. Rescue by anthranilate/indole/tryptophan demonstrates specific impairment of the first committed step of Trp biosynthesis rather than a broad growth defect. | (pqac-00000001, pqac-00000002, pqac-00000012) | Molina-Henares et al. (Dec 2009): https://doi.org/10.1111/j.1751-7915.2008.00062.x |
| Applications / engineering | KT2440 has been engineered to accumulate **anthranilate** by deleting **trpDC** and overexpressing **feedback-insensitive trpE/trpG** variants. In fed-batch, the best reported strain reached **1.54 ± 0.3 g/L anthranilate (11.23 mM)** from glucose. TrpE is thus a practical flux-control node for aromatic biomanufacturing. | (pqac-00000004) | Kuepper et al., *Frontiers in Microbiology* (Nov 2015): https://doi.org/10.3389/fmicb.2015.01310 |
| Recent developments (2023–2024) | Recent work emphasizes (i) **structure-guided deregulation** of anthranilate synthase feedback inhibition, including residue-level analysis of Trp and chorismate binding; (ii) **PPI-targeted antibiotic strategies** aimed at the conserved TrpG–TrpE interface; and (iii) renewed interest in aromatic-pathway rewiring for high-yield production platforms. | (pqac-00000007, pqac-00000008, pqac-00000010, pqac-00000011) | Naz et al. (Aug 2023): https://doi.org/10.1186/s12934-023-02178-z; Funke et al. (May 2024): https://doi.org/10.1128/aem.00572-24 |
| Statistics / data | Quantitative findings include: **1.54 ± 0.3 g/L (11.23 mM)** anthranilate in engineered KT2440; Funke et al. analyzed conservation across **~695 bacterial AS/ADCS sequences** to identify interface hotspots; Molina-Henares et al. isolated **four tryptophan auxotrophs** in KT2440 mutagenesis, including a **trpE** mutant. | (pqac-00000004, pqac-00000011, pqac-00000012) | Kuepper et al. (Nov 2015): https://doi.org/10.3389/fmicb.2015.01310; Funke et al. (May 2024): https://doi.org/10.1128/aem.00572-24; Molina-Henares et al. (Dec 2009): https://doi.org/10.1111/j.1751-7915.2008.00062.x |


*Table: This table summarizes the validated functional annotation of *Pseudomonas putida* KT2440 trpE (UniProt Q88QS1 / PP_0417), covering biochemical function, gene organization, phenotypes, engineering uses, and recent 2023–2024 developments with direct context-ID citations.*