PP_4983 is an exported FAD-dependent amine oxidase family protein in Pseudomonas putida KT2440. The locus is often discussed under the alias iaaM because UniProt/GO automation assigns tryptophan 2-monooxygenase activity and auxin biosynthesis to it, but the specific iaaM interpretation is weak. The same locus is annotated by KEGG as a putative amine oxidase / monoamine oxidase (K00274, EC 1.4.3.4), and KT2440 already contains distinct amino oxidase family members including davB/PP_0383. The best current synthesis is monoamine-oxidase-like oxidoreductase activity with unresolved physiological substrate, rather than a confirmed indole-3-acetamide auxin-biosynthetic enzyme.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0016491 oxidoreductase activity | IEA GO_REF:0000120 | MARK AS OVER ANNOTATED | Summary: PP_4983 is clearly an oxidoreductase-family protein, but this parent term is too broad to be useful. Both UniProt and KEGG place the protein within flavin-dependent amine oxidation chemistry, so a more specific amine-oxidase-like molecular function is preferable. Reason: The broad oxidoreductase root term adds little information once the locus is interpreted as a monoamine-oxidase-like flavoprotein. It is directionally correct but not an informative core annotation. Supporting Evidence: file:PSEPK/iaaM/iaaM-notes.md The safest current synthesis is amine oxidase / monoamine oxidase-like flavoprotein rather than confirmed tryptophan 2-monooxygenase in auxin biosynthesis. |
| GO:0050361 tryptophan 2-monooxygenase activity | IEA GO_REF:0000003 | MODIFY | Summary: This specific iaaM-style annotation is not well supported for PP_4983. The UniProt assignment is homology-based only, whereas KEGG classifies the same locus as a putative amine oxidase / monoamine oxidase and not as a dedicated indole-3-acetamide auxin enzyme. In the same genome, davB/PP_0383 is already assigned a distinct amino-oxidase chemistry, reinforcing that automatic family transfer is likely overspecific here. Reason: The protein is probably an amine oxidase, but the specific substrate assignment to tryptophan-to-indole-3-acetamide conversion is weaker than the broader monoamine oxidase interpretation from KEGG. Until biochemical data establish IAM formation in KT2440, the safer molecular function is monoamine oxidase activity. Proposed replacements: monoamine oxidase activity Supporting Evidence: file:PSEPK/iaaM/iaaM-uniprot.txt Belongs to the tryptophan 2-monooxygenase family. file:PSEPK/iaaM/iaaM-uniprot.txt PE 3: Inferred from homology; file:PSEPK/iaaM/iaaM-notes.md KEGG contradicts the specific iaaM call for the same locus and instead labels PP_4983 as putative amine oxidase with orthology K00274 monoamine oxidase [EC:1.4.3.4]. |
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Download this section (compressed HTML)Q: Is PP_4983 able to convert L-tryptophan to indole-3-acetamide in vitro or in vivo, or is its physiological substrate a different monoamine?
Q: Does KT2440 encode a bona fide iaaH-like amidase that pairs with PP_4983 in an indole-3-acetamide pathway?
Experiment: Purify PP_4983 and test FAD-dependent oxidation of L-tryptophan, methylamine, phenethylamine, tyramine, and related amines by LC-MS or targeted product assays. Compare turnover against authentic indole-3-acetamide production.
Hypothesis: PP_4983 is a monoamine oxidase-like flavoprotein rather than a dedicated iaaM tryptophan 2-monooxygenase.
Type: biochemical enzyme assay
Experiment: Construct a PP_4983 deletion strain and quantify indole-3-acetamide and indole-3-acetic acid in wild type and mutant cultures grown with supplemental tryptophan.
Hypothesis: If PP_4983 participates in IAM/IAA biosynthesis, deleting the locus should reduce indole-3-acetamide or indole-3-acetic acid accumulation from tryptophan.
Type: genetics plus metabolomics
Experiment: Compare PP_4983, PP_4155, and davB mutant growth and transcriptional responses across candidate amine and amino-acid substrates to separate auxin-pathway and general amine-catabolic roles.
Hypothesis: PP_4983 and the other KT2440 amine oxidase candidates have distinct substrate scopes.
Type: comparative genetics and physiology
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