TrpE (PA0609) is the large (component I) subunit of anthranilate synthase, the first enzyme of L-tryptophan biosynthesis in Pseudomonas aeruginosa. With the glutamine-amidotransferase subunit TrpG it forms a heterotetramer that converts chorismate and L-glutamine to anthranilate, pyruvate and glutamate (EC 4.1.3.27); TrpE carries the chorismate-binding/aminating active site and is feedback-inhibited by tryptophan. P. aeruginosa has a second, paralogous anthranilate synthase, PhnAB, that supplies anthranilate for pyocyanin rather than for tryptophan; the two are not functionally redundant because trpEG is expressed at low cell density while phnAB is expressed at high density. trpE deletion causes tryptophan auxotrophy.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000162 L-tryptophan biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from the PTN002599563 IBD (L-tryptophan biosynthetic process), seeded by eight experimental annotations across bacteria, yeast, fission yeast and plants (B. subtilis TrpE P00895 IDA/IMP, S. cerevisiae TRP2, S. pombe, Arabidopsis AT5G05730, M. tuberculosis P9WFX3, and P. aeruginosa TrpE itself). TrpE in its own WITH/FROM is expected. The process term is correct for this deeply conserved enzyme family. Reason: TrpE catalyses the first step of tryptophan biosynthesis; the node term holds across the clade. Supporting Evidence: PMID:23449919 This reaction is also the first step in tryptophan biosynthesis PMID:23449919 trpEG mutants are tryptophan auxotrophs but produce PQS |
| GO:0000162 L-tryptophan biosynthetic process | IEA GO_REF:0000120 | ACCEPT | Summary: UniRule/InterPro/UniPathway assignment to tryptophan biosynthesis. Reason: Consistent with the enzyme's pathway step. Supporting Evidence: PMID:23449919 This reaction is also the first step in tryptophan biosynthesis file:PSEAE/trpE/trpE-uniprot.txt Belongs to the anthranilate synthase component I family |
| GO:0000162 L-tryptophan biosynthetic process | IMP PMID:2153661 Identification and characterization of genes for a second an... | ACCEPT | Summary: PseudoCAP IMP and one of the eight seeds of the PTN002599563 IBD. The abstract shows that a chromosomal trpE deletion makes P. aeruginosa a tryptophan auxotroph and that trpE (with trpG) is the tryptophan-synthesis anthranilate synthase, distinct from the pyocyanin enzyme phnAB. Reason: Sound seed. Loss-of-function auxotrophy places TrpE in the tryptophan biosynthetic process. Supporting Evidence: PMID:2153661 This resulted in tryptophan auxotrophy PMID:2153661 its genes are designated trpE and trpG |
| GO:0004049 anthranilate synthase activity | IEA GO_REF:0000120 | ACCEPT | Summary: InterPro/RHEA/EC assignment of anthranilate synthase activity. Matches the UniProt catalytic-activity line (RHEA:21732, EC 4.1.3.27). Reason: Core catalytic activity of the TrpE subunit. Supporting Evidence: file:PSEAE/trpE/trpE-uniprot.txt Reaction=chorismate + L-glutamine = anthranilate + pyruvate + L- file:PSEAE/trpE/trpE-uniprot.txt Belongs to the anthranilate synthase component I family |
| GO:0004049 anthranilate synthase activity | IMP PMID:2153661 Identification and characterization of genes for a second an... | ACCEPT | Summary: PseudoCAP IMP to anthranilate synthase activity. The paper is genetic (auxotrophy of the trpE knockout, interchangeability of the two anthranilate synthases) rather than an in vitro assay on PA TrpE, but it establishes that trpE encodes a functional anthranilate synthase subunit. Reason: The activity is correct for TrpE and is supported by the auxotrophy and complementation genetics plus the curated reaction. The evidence is genetic, so it supports the process directly and the activity by inference. Supporting Evidence: PMID:2153661 This resulted in tryptophan auxotrophy PMID:23449919 P. aeruginosa possesses two functional anthranilate synthases, TrpEG and PhnAB file:PSEAE/trpE/trpE-uniprot.txt Reaction=chorismate + L-glutamine = anthranilate + pyruvate + L- |
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Download this section (compressed HTML)Q: Does the amount of flux through TrpEG versus PhnAB explain why only phnAB loss abolishes pyocyanin, and is there any condition where TrpE supplies anthranilate for pyocyanin in vivo?
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