NaODC_candidate_DCOR is a competing ODC-like paralog in the polyamine branch that feeds nicotine biosynthesis. It is clearly an ornithine decarboxylase family enzyme, but current evidence still favors the ODC accession over DCOR as the primary pathway-specialized copy.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003824 catalytic activity | IEA GO_REF:0000002 | MARK AS OVER ANNOTATED | Summary: This parent catalytic term is too generic. Reason: GO:0004586 already captures the specific chemistry of the DCOR candidate. |
| GO:0004586 ornithine decarboxylase activity | IEA GO_REF:0000120 | ACCEPT | Summary: This specific activity annotation is appropriate. Reason: DCOR is clearly part of the ornithine decarboxylase family and retains the same underlying decarboxylase chemistry. Supporting Evidence: file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-notes.md UniProt curates A0A1J6ITS2 as an ornithine decarboxylase-family enzyme that catalyzes the same PLP-dependent ornithine-to-putrescine reaction and is also assigned to nicotine biosynthesis. |
| GO:0005737 cytoplasm | IEA GO_REF:0000118 | REMOVE | Summary: Cytoplasm is not the best-supported location for this candidate. Reason: UniProt supports chloroplast/plastid localization instead of cytoplasm for this accession. Supporting Evidence: file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-uniprot.txt CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast |
| GO:0006596 polyamine biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: This process assignment is appropriate. Reason: Ornithine decarboxylase chemistry directly feeds polyamine biosynthesis via putrescine formation. |
| GO:0009507 chloroplast | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Chloroplast localization should be retained as non-core context. Reason: The location is supported, but it is less important than resolving the pathway-specialized ODC paralog. Supporting Evidence: file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-uniprot.txt CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast |
| GO:0033387 putrescine biosynthetic process from arginine, via ornithine | IEA GO_REF:0000120 | MODIFY | Summary: The ornithine-route putrescine term was the appropriate upstream process, but it is now obsolete; its replacement, putrescine biosynthetic process, is the correct upstream term. Reason: DCOR still encodes ornithine-to-putrescine chemistry even if its precise nicotine specialization remains uncertain. GO:0033387 is obsolete in the GO release 2026-07-26 (replaced_by GO:0009446), so the annotation moves to putrescine biosynthetic process. Proposed replacements: putrescine biosynthetic process Supporting Evidence: file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-notes.md UniProt curates A0A1J6ITS2 as an ornithine decarboxylase-family enzyme that catalyzes the same PLP-dependent ornithine-to-putrescine reaction and is also assigned to nicotine biosynthesis. |
| GO:0042179 nicotine biosynthetic process | IEA GO_REF:0000041 | KEEP AS NON CORE | Summary: DCOR remains a plausible nicotine-pathway paralog, but the current evidence is not decisive. Reason: Retain the pathway assignment as a live possibility while acknowledging that ODC is currently the stronger project mapping. Supporting Evidence: file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-notes.md DCOR remains a plausible NaODC1/NaODC2 candidate, but current public annotations alone do not show whether it is the specialized nicotine-pathway paralog or a related housekeeping copy. |
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Download this section (compressed HTML)Q: Is DCOR catalytically equivalent to the stronger ODC candidate, or has it diverged in expression or substrate context?
Q: Does DCOR contribute measurable flux to nicotine biosynthesis or function mainly as a noncore decarboxylase paralog?
Experiment: Compare DCOR and ODC enzymatic activity and expression across root nicotine-inducing conditions.
Hypothesis: DCOR remains catalytically competent but is less tightly coupled to nicotine production than the leading ODC candidate.
Type: comparative biochemistry and expression profiling
Experiment: Measure nicotine-pathway metabolites after selective DCOR perturbation and compare with the primary ODC candidate.
Hypothesis: DCOR has a weaker nicotine phenotype than the leading ODC accession.
Type: comparative genetics plus metabolite profiling
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