NaODC_candidate_DCOR Notes

• 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. [file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-uniprot.txt "DE RecName: Full=ornithine decarboxylase"; "CC -!- CATALYTIC ACTIVITY: Reaction=L-ornithine + H(+) = putrescine + CO2"; "CC -!- PATHWAY: Alkaloid biosynthesis; nicotine biosynthesis."; "CC -!- PATHWAY: Amine and polyamine biosynthesis; putrescine biosynthesis via L-ornithine pathway; putrescine from L-ornithine: step 1/1."]
• UniProt places this candidate in plastid/chloroplast and in the same class-II ornithine/lysine/arginine decarboxylase family, so DCOR is not an unrelated decarboxylase but a bona fide competing ODC-like paralog. [file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-uniprot.txt "CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast"; "CC -!- SIMILARITY: Belongs to the Orn/Lys/Arg decarboxylase class-II family."; "DR PANTHER; PTHR11482:SF6; ORNITHINE DECARBOXYLASE 1-RELATED; 1."]
• The N. attenuata genome paper makes duplicated polyamine-pathway ancestry a central feature of nicotine-pathway evolution, which is exactly why the ODC versus DCOR split has to be reviewed explicitly. PMID:28536194
• The full glucosylation preprint keeps the upstream ODC-PMT-MPO module inside the minimal reconstituted pathway, so even a competing DCOR-like paralog remains relevant until the ODC-family split is resolved directly. [file:projects/NICOTINE_BIOSYNTHESIS/biorxiv-nicotine-glucosylation-notes.md "In N. benthamiana leaves, the in planta reconstruction uses ODC, PMT, and MPO to generate N-methylpyrrolinium, then depends on the glucosylation-late-pathway module to make labelled nicotine"; "ODC, PMT, and MPO remain part of the minimal upstream module needed to feed the completed pathway."]
• 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. [file:NICAT/NaODC_candidate_DCOR/NaODC_candidate_DCOR-uniprot.txt "GN Name=DCOR"; "CC -!- PATHWAY: Alkaloid biosynthesis; nicotine biosynthesis."]