B0EXJ8 · HTOMT_CATRO
- ProteinTabersonine 16-O-methyltransferase
- Gene16OMT
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids355 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
16-O-methyltransferase involved in the biosynthesis of vindoline. Highly specific for 16-hydroxytabersonine. No activity with tabersonine, 3-hydroxytyramine, 4-hydroxytyramine, 5-hydroxytryptamine (5HT), 2,3-dihydro-3-hydroxytabersonine, lochnericine, hoerhammericine, 16-hydroxy-2,3-dihydro-3-hydroxytabersonine, 16-hydroxylochnericine, 16-hydroxyhoerhammericine, quercetin, kaempferol and caffeic acid as substrates.
Catalytic activity
- 16-hydroxytabersonine + S-adenosyl-L-methionine = 16-methoxytabersonine + H+ + S-adenosyl-L-homocysteine
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
2.6 μM | 16-hydroxytabersonine | |||||
21.7 μM | S-adenosyl-L-methionine |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
0.58 mmol/sec/mg | toward 16-hydroxytabersonine | ||||
0.79 mmol/sec/mg | toward S-adenosyl-L-methionine |
pH Dependence
Optimum pH is 7.0-7.5.
Pathway
Alkaloid biosynthesis; vindoline biosynthesis.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 198-201 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: IGGG | ||||||
Binding site | 222 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 222-223 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: DL | ||||||
Binding site | 242-243 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: DM | ||||||
Binding site | 256 | S-adenosyl-L-methionine (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Active site | 260 | Proton acceptor | ||||
Sequence: H |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | 11-O-demethyl-17-O-deacetylvindoline O-methyltransferase activity | |
Molecular Function | O-methyltransferase activity | |
Molecular Function | protein homodimerization activity | |
Biological Process | alkaloid biosynthetic process | |
Biological Process | methylation |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameTabersonine 16-O-methyltransferase
- EC number
Gene names
Organism names
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > asterids > lamiids > Gentianales > Apocynaceae > Rauvolfioideae > Vinceae > Catharanthinae > Catharanthus
Accessions
- Primary accessionB0EXJ8
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000412068 | 1-355 | Tabersonine 16-O-methyltransferase | |||
Sequence: MDVQSEEFRGAQAQIWSQSCSFITSASLKCAVKLGIPDTIDNHGKPITLSELTNALVPPVHPSKAPFIYRLMRVLAKNGFCSEEQLDGETEPLYSLTPSSRILLKKEPLNLRGIVLTMADPVQLKAWESLSDWYQNEDDSSTAFETAHGKNFWGYSSEHMEHAEFFNEAMASDSQLISKLLIGEYKFLFEGLASLVDIGGGTGTIAKAIAKNFPQLKCTVFDLPHVVANLESKENVEFVAGDMFEKIPSANAIFLKWILHDWNDEDCVKILKSCKKAIPAKGGKVIIIDMVMYSDKKDDHLVKTQTSMDMAMLVNFAAKERCEKEWAFLFKEAGFSDYKIYPKLDFTRSLIEVYP |
Expression
Tissue specificity
Expressed in leaves and flowers. Detected in stems and roots. In leaves, expressed in epidermal cells.
Induction
Up-regulated by herbivory.
Developmental stage
Peak of expression in 8-day-old seedlings. Highest expression in the youngest leaf pair.
Interaction
Subunit
Homodimer.
Structure
Family & Domains
Sequence similarities
Belongs to the class I-like SAM-binding methyltransferase superfamily. Cation-independent O-methyltransferase family. COMT subfamily.
Family and domain databases
Sequence
- Sequence statusComplete
- Length355
- Mass (Da)39,863
- Last updated2008-02-26 v1
- Checksum76E6CB586E427CA5
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
EF444544 EMBL· GenBank· DDBJ | ABR20103.1 EMBL· GenBank· DDBJ | mRNA |