MetaCyc Enzyme: norcoclaurine synthase

Gene: NCS1 Accession Number: G-10573 (MetaCyc)

Species: Coptis japonica dissecta

CjNCS1 encodes the major norcoclaurine synthase in Coptis japonica. The enzyme catalyzes stereo-specific formation of (S)-norcoclaurine from dopamine and 4-hydroxyphenylacetaldehyde, and is Fe2+-dependent. Among the amines tested, CjNCS1 only accepted dopamine, but not tyramine and tryptamine. On the other hand, besides 4-hydroxyphenylacetaldehyde, the enzyme also reacted with phenylacetaldehyde and 3,4-dihydroxyphenylacetaldehyde.

The sequence of CjNCS1 shares no homology to the NCS gene in T. flavum. The T. flavum NCS homolog in C. japonica, CjPR10A, also has norcoclaurine synthase activity in vitro. It may represent a minor norcoclaurine synthase in vivo. CjPR10A also catalyzes the condensation of dopamine with 4-hydroxyphenylpyruvate.

Locations: cytosol

Molecular Weight of Polypeptide: 40.0 kD (experimental) [Minami07 ]

Relationship Links: Entrez-Nucleotide:PART-OF:AB267398

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Cellular Component: GO:0005829 - cytosol [Minami07]

Created 26-Mar-2008 by Zhang P , TAIR

Enzymatic reaction of: norcoclaurine synthase

EC Number:

dopamine + (4-hydroxyphenyl)acetaldehyde <=> (S)-norcoclaurine + H2O

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 favored in the direction shown.

Alternative Substrates for (4-hydroxyphenyl)acetaldehyde: phenylacetaldehyde [Minami07 ] , 3,4-dihydroxyphenylacetaldehyde [Minami07 ]

In Pathways: (S)-reticuline biosynthesis I

Cofactors or Prosthetic Groups: Fe2+ [Minami07]

Inhibitors (Unknown Mechanism): o-phenanthroline [Minami07]


Minami07: Minami H, Dubouzet E, Iwasa K, Sato F (2007). "Functional analysis of norcoclaurine synthase in Coptis japonica." J Biol Chem 282(9);6274-82. PMID: 17204481

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 19.0 on Mon Oct 5, 2015, BIOCYC14A.