Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
twitter

MetaCyc Enzyme: columbamine O-methyltransferase

Gene: CoOMT Accession Number: G-9901 (MetaCyc)

Species: Coptis japonica

Molecular Weight of Polypeptide: 40 kD (experimental) [Morishige02 ]

Relationship Links: Entrez-Nucleotide:PART-OF:AB073908

Gene-Reaction Schematic: ?


Enzymatic reaction of: S-adenosyl-L-methionine:columbamine O-methyltransferase

EC Number: 2.1.1.118

S-adenosyl-L-methionine + columbamine <=> S-adenosyl-L-homocysteine + palmatine + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is physiologically favored in the direction shown.

In Pathways: palmatine biosynthesis

Summary:
Both columbamine and tetrahydrocolumbamine are good substrates for the C. japonica enzyme, indicating palmatine biosynthesis can proceed via either columbamine or tetrahydropalmatine, at least in C. japonica. The enzyme substrate specificity is different from that reported from Berberis. The Berberis wilsoniae enzyme is highly substrate specific [Rueffer86]. Only columbamine, not tetrahydrocolumbamine, served as the substrate.

Kinetic Parameters:

Substrate
Km (μM)
Citations
columbamine
66.0
[Morishige02]

pH(opt): 8.4 [Morishige02]


Enzymatic reaction of: S-adenosyl-L-methionine:S-tetrahydrocolumbamine O-methyltransferase

EC Number: 2.1.1.89

S-tetrahydrocolumbamine + S-adenosyl-L-methionine <=> S-adenosyl-L-homocysteine + tetrahydropalmatine + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is physiologically favored in the direction shown.

Alternative Substrates for S-tetrahydrocolumbamine: (S)-scoulerine [Morishige02 ] , columbamine [Morishige02 ]

In Pathways: palmatine biosynthesis

Summary:
Both columbamine and tetrahydrocolumbamine are good substrates for the C. japonica enzyme, indicating palmatine biosynthesis can proceed via either columbamine or tetrahydropalmatine, at least in C. japonica. The enzyme substrate specificity is different from that reported from Berberis. The Berberis wilsoniae enzyme is highly substrate specific [Rueffer86]. Only columbamine, not tetrahydrocolumbamine, served as the substrate.

Kinetic Parameters:

Substrate
Km (μM)
Citations
S-tetrahydrocolumbamine
35.0
[Morishige02]

pH(opt): 8.4 [Morishige02]


References

Morishige02: Morishige T, Dubouzet E, Choi KB, Yazaki K, Sato F (2002). "Molecular cloning of columbamine O-methyltransferase from cultured Coptis japonica cells." Eur J Biochem 269(22);5659-67. PMID: 12423366

Rueffer86: Rueffer, M, Amann, M, Zenk, MH (1986). "S-adenosyl-methionine: columbamine-O-methyltransferase, a compartmentalized enzyme in protoberberine biosynthesis." Plant Cell Reports 3:182-185.


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Sat Nov 22, 2014, biocyc13.