The Enzyme Database

Your query returned 16 entries.    printer_iconPrintable version



EC 1.5.1.27     
Accepted name: 1,2-dehydroreticulinium reductase (NADPH)
Reaction: (R)-reticuline + NADP+ = 1,2-dehydroreticulinium + NADPH + H+
For diagram of thebaine biosynthesis, click here
Other name(s): 1,2-dehydroreticulinium ion reductase
Systematic name: (R)-reticuline:NADP+ oxidoreductase
Comments: Reduces the 1,2-dehydroreticulinium ion to (R)-reticuline, which is a direct precursor of morphinan alkaloids in the poppy plant. The enzyme does not catalyse the reverse reaction to any significant extent under physiological conditions.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 130590-58-8
References:
1.  De-Eknamkul, W. and Zenk, M.H. Purification and properties of 1,2-dehydroreticulinium reductase from Papaver somniferum seedlings. Phytochemistry 31 (1992) 813–821.
[EC 1.5.1.27 created 1999, modified 2004]
 
 
EC 1.5.3.9      
Transferred entry: reticuline oxidase. Now EC 1.21.3.3, reticuline oxidase
[EC 1.5.3.9 created 1989, modified 1999, deleted 2002]
 
 
EC 1.14.13.71      
Transferred entry: N-methylcoclaurine 3′-monooxygenase. Now EC 1.14.14.102, N-methylcoclaurine 3′-monooxygenase
[EC 1.14.13.71 created 2001, deleted 2018]
 
 
EC 1.14.14.102     
Accepted name: N-methylcoclaurine 3′-monooxygenase
Reaction: (S)-N-methylcoclaurine + [reduced NADPH—hemoprotein reductase] + O2 = (S)-3′-hydroxy-N-methylcoclaurine + [oxidized NADPH—hemoprotein reductase] + H2O
For diagram of reticuline biosynthesis, click here
Other name(s): N-methylcoclaurine 3′-hydroxylase; CYP80B1 (gene name)
Systematic name: (S)-N-methylcoclaurine,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (3′-hydroxylating)
Comments: A cytochrome P-450 (heme-thiolate) protein involved in benzylisoquinoline alkaloid synthesis in higher plants.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 202420-37-9
References:
1.  Pauli, H.H. and Kutchan, T.M. Molecular cloning and functional heterologous expression of two alleles encoding (S)-N-methylcoclaurine 3′-hydroxylase (CYP80B1), a new methyl jasmonate-inducible cytochrome P-450-dependent mono-oxygenase of benzylisoquinoline alkaloid biosynthesis. Plant J. 13 (1998) 793–801. [DOI] [PMID: 9681018]
[EC 1.14.14.102 created 2001 as 1.14.13.71, transferred 2018 to EC 1.14.14.102]
 
 
EC 1.14.19.51     
Accepted name: (S)-corytuberine synthase
Reaction: (S)-reticuline + [reduced NADPH—hemoprotein reductase] + O2 = (S)-corytuberine + [oxidized NADPH—hemoprotein reductase] + 2 H2O.
For diagram of corytuberine and magnoflorine biosynthesis, click here
Other name(s): CYP80G2
Systematic name: (S)-reticuline,NADPH:oxygen oxidoreductase (C-C phenol-coupling; (S)-corytuberine-forming)
Comments: A cytochrome P-450 (heme-thiolate) protein. The enzyme is involved in the biosynthesis of the quaternary benzylisoquinoline alkaloid magnoflorine in the plant Coptis japonica. It is specific for (S)-reticuline.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Ikezawa, N., Iwasa, K. and Sato, F. Molecular cloning and characterization of CYP80G2, a cytochrome P450 that catalyzes an intramolecular C-C phenol coupling of (S)-reticuline in magnoflorine biosynthesis, from cultured Coptis japonica cells. J. Biol. Chem. 283 (2008) 8810–8821. [DOI] [PMID: 18230623]
[EC 1.14.19.51 created 2017]
 
 
EC 1.14.19.54     
Accepted name: 1,2-dehydroreticuline synthase
Reaction: (S)-reticuline + [reduced NADPH—hemoprotein reductase] + O2 = 1,2-dehydroreticuline + [oxidized NADPH—hemoprotein reductase] + 2 H2O
For diagram of thebaine biosynthesis, click here
Glossary: reticuline = 1-(3-hydroxy-4-methoxybenzyl)-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-7-ol
Other name(s): STORR; CYP82Y2 (gene name); DRS (gene name)
Systematic name: (S)-reticuline,[reduced NADPH—hemoprotein reductase]:oxygen 1,2-oxidoreductase
Comments: A P-450 (heme-thiolate) cytochrome. The enzyme from Papaver rhoeas (field poppy) is specific for (S)-reticuline and does not act on the (R)-form. The enzyme from Papaver somniferum (opium poppy), which is involved in the biosynthesis of morphine and related alkaloids, forms a fusion protein with EC 1.5.1.27, 1,2-dehydroreticulinium reductase (NADPH), which catalyses the reduction of 1,2-dehydroreticuline to (R)-reticuline, thus forming an epimerase system that converts (S)-reticuline to (R)-reticuline.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Hirata, K., Poeaknapo, C., Schmidt, J. and Zenk, M.H. 1,2-Dehydroreticuline synthase, the branch point enzyme opening the morphinan biosynthetic pathway. Phytochemistry 65 (2004) 1039–1046. [DOI] [PMID: 15110683]
2.  Winzer, T., Kern, M., King, A.J., Larson, T.R., Teodor, R.I., Donninger, S.L., Li, Y., Dowle, A.A., Cartwright, J., Bates, R., Ashford, D., Thomas, J., Walker, C., Bowser, T.A. and Graham, I.A. Morphinan biosynthesis in opium poppy requires a P450-oxidoreductase fusion protein. Science 349 (2015) 309–312. [DOI] [PMID: 26113639]
3.  Farrow, S.C., Hagel, J.M., Beaudoin, G.A., Burns, D.C. and Facchini, P.J. Stereochemical inversion of (S)-reticuline by a cytochrome P450 fusion in opium poppy. Nat. Chem. Biol. 11 (2015) 728–732. [DOI] [PMID: 26147354]
[EC 1.14.19.54 created 2018]
 
 
EC 1.14.19.67     
Accepted name: salutaridine synthase
Reaction: (R)-reticuline + [reduced NADPH—hemoprotein reductase] + O2 = salutaridine + [oxidized NADPH—hemoprotein reductase] + 2 H2O
For diagram of thebaine biosynthesis, click here
Other name(s): (R)-reticuline oxidase (C-C phenol-coupling)
Systematic name: (R)-reticuline,[reduced NADPH—hemoprotein reductase]:oxygen oxidoreductase (C-C phenol-coupling)
Comments: A cytochrome P-450 (heme-thiolate) protein found in plants. Forms the morphinan alkaloid salutaridine by intramolecular phenol oxidation of reticuline without the incorporation of oxygen into the product.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 149433-84-1
References:
1.  Gerady, R. and Zenk, M.H. Formation of salutaridine from (R)-reticuline by a membrane-bound cytochrome P-450 enzyme from Papaver somniferum. Phytochemistry 32 (1993) 79–86.
[EC 1.14.19.67 created 1999 as EC 1.1.3.35, transferred 2002 to EC 1.14.21.4, transferred 2018 to EC 1.14.19.67]
 
 
EC 1.14.21.4      
Transferred entry: salutaridine synthase. Now EC 1.14.19.67, salutaridine synthase
[EC 1.14.21.4 created 2002, deleted 2018]
 
 
EC 1.21.3.3     
Accepted name: reticuline oxidase
Reaction: (S)-reticuline + O2 = (S)-scoulerine + H2O2
For diagram of stylopine biosynthesis, click here
Other name(s): BBE; berberine bridge enzyme; berberine-bridge-forming enzyme; tetrahydroprotoberberine synthase
Systematic name: (S)-reticuline:oxygen oxidoreductase (methylene-bridge-forming)
Comments: Contains FAD. The enzyme from the plant Eschscholtzia californica binds the cofactor covalently [3]. Acts on (S)-reticuline and related compounds, converting the N-methyl group into the methylene bridge (’berberine bridge’) of (S)-tetrahydroprotoberberines. The product of the reaction, (S)-scoulerine, is a precursor of protopine, protoberberine and benzophenanthridine alkaloid biosynthesis in plants.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 152232-28-5
References:
1.  Steffens, P., Nagakura, N. and Zenk, M.H. The berberine bridge forming enzyme in tetrahydroprotoberberine biosynthesis. Tetrahedron Lett. 25 (1984) 951–952.
2.  Dittrich, H. and Kutchan, T.M. Molecular cloning, expression and induction of the berberine bridge enzyme, an enzyme essential to the formation of benzophenanthridine alkaloids in the response of plants to pathogenic attack. Proc. Natl. Acad. Sci. USA 88 (1991) 9969–9973. [DOI] [PMID: 1946465]
3.  Kutchan, T.M. and Dittrich, H. Characterization and mechanism of the berberine bridge enzyme, a covalently flavinylated oxidase of benzophenanthridine alkaloid biosynthesis in higher plants. J. Biol. Chem. 270 (1995) 24475–24481. [DOI] [PMID: 7592663]
[EC 1.21.3.3 created 1989 as EC 1.5.3.9, transferred 2002 to EC 1.21.3.3]
 
 
EC 2.1.1.115     
Accepted name: (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase
Reaction: S-adenosyl-L-methionine + (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline = S-adenosyl-L-homocysteine + N-methyl-(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline
Other name(s): norreticuline N-methyltransferase
Systematic name: S-adenosyl-L-methionine:(RS)-1-benzyl-1,2,3,4-tetrahydroisoquinoline N-methyltransferase
Comments: Broad substrate specificity for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines; including coclaurine, norcoclaurine, isococlaurine, norarmepavine, norreticuline and tetrahydropapaverine. Both R- and S-enantiomers are methylated. The enzyme participates in the pathway leading to benzylisoquinoline alkaloid synthesis in plants. The physiological substrate is likely to be coclaurine. The enzyme was earlier termed norreticuline N-methyltransferase. However, norreticuline has not been found to occur in nature and that name does not reflect the broad specificity of the enzyme for (RS)-1-benzyl-1,2,3,4-tetrahydroisoquinolines.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 132084-82-3
References:
1.  Frenzel, T., Zenk, M.H. Purification and characterization of three isoforms of S-adenosyl-L-methionine: (R,S)-tetrahydrobenzyl-isoquinoline N-methyltransferase from Berberis koetineana cell cultures. Phytochemistry 29 (1990) 3491–3497.
[EC 2.1.1.115 created 1999]
 
 
EC 2.1.1.116     
Accepted name: 3′-hydroxy-N-methyl-(S)-coclaurine 4′-O-methyltransferase
Reaction: S-adenosyl-L-methionine + 3′-hydroxy-N-methyl-(S)-coclaurine = S-adenosyl-L-homocysteine + (S)-reticuline
For diagram of reticuline biosynthesis, click here
Systematic name: S-adenosyl-L-methionine:3′-hydroxy-N-methyl-(S)-coclaurine 4′-O-methyltransferase
Comments: Involved in isoquinoline alkaloid metabolism in plants. The enzyme has also been shown to catalyse the methylation of (RS)-laudanosoline, (S)-3′-hydroxycoclaurine and (RS)-7-O-methylnorlaudanosoline.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 132084-81-2
References:
1.  Frenzel, T., Zenk, M.H. S-Adenosyl-L-methionine: 3′-hydroxy-N-methyl-(S)-coclaurine 4′-O-methyltransferase, a regio- and stereoselective enzyme of the (S)-reticuline pathway. Phytochemistry 29 (1990) 3505–3511. [DOI]
[EC 2.1.1.116 created 1999]
 
 
EC 2.1.1.128     
Accepted name: (RS)-norcoclaurine 6-O-methyltransferase
Reaction: S-adenosyl-L-methionine + (RS)-norcoclaurine = S-adenosyl-L-homocysteine + (RS)-coclaurine
For diagram of reticuline biosynthesis, click here
Glossary: norcoclaurine = 6,7-dihydroxy-1-[(4-hydroxyphenyl)methyl]-1,2,3,4-tetrahydroisoquinoline
Systematic name: S-adenosyl-L-methionine:(RS)-norcoclaurine 6-O-methyltransferase
Comments: The enzyme will also catalyse the 6-O-methylation of (RS)-norlaudanosoline to form 6-O-methyl-norlaudanosoline, but this alkaloid has not been found to occur in plants.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 89700-33-4
References:
1.  Rueffer, M., Nagakura, N., Zenk, M.H. Partial purification and properties of S-adenosyl-L-methionine:(R),(S)-norlaudanosoline-6-O-methyltransferase from Argemone platyceras cell cultures. Planta Med. 49 (1983) 131–137. [PMID: 17405035]
2.  Sato, F., Tsujita, T., Katagiri, Y., Yoshida, S. and Yamada, Y. Purification and characterization of S-adenosyl-L-methionine:norcoclaurine 6-O-methyltransferase from cultured Coptis japonica cells. Eur. J. Biochem. 225 (1994) 125–131. [DOI] [PMID: 7925429]
3.  Stadler, R., Zenk, M.H. A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline. Liebigs Ann. Chem. (1990) 555–562.
[EC 2.1.1.128 created 1999]
 
 
EC 2.1.1.140     
Accepted name: (S)-coclaurine-N-methyltransferase
Reaction: S-adenosyl-L-methionine + (S)-coclaurine = S-adenosyl-L-homocysteine + (S)-N-methylcoclaurine
For diagram of reticuline-biosynthesis pathway, click here
Systematic name: S-adenosyl-L-methionine:(S)-coclaurine-N-methyltransferase
Comments: The enzyme is specific for the (S)-isomer of coclaurine. Norcoclaurine can also act as an acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 167398-06-3
References:
1.  Loeffler, S., Deus-Neumann, B. and Zenk, M.H. S-Adenosyl-L-methionine: (S)-coclaurine-N-methyltransferase from Tinospora cordifolia. Phytochemistry 38 (1995) 1387–1395. [DOI]
[EC 2.1.1.140 created 2001]
 
 
EC 2.1.1.291     
Accepted name: (R,S)-reticuline 7-O-methyltransferase
Reaction: (1) S-adenosyl-L-methionine + (S)-reticuline = S-adenosyl-L-homocysteine + (S)-laudanine
(2) S-adenosyl-L-methionine + (R)-reticuline = S-adenosyl-L-homocysteine + (R)-laudanine
For diagram of laudanine biosynthesis, click here
Glossary: (S)-reticuline = (1S)-1-[(3-hydroxy-4-methoxyphenyl)methyl]-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-7-ol
(R)-reticuline = (1R)-1-[(3-hydroxy-4-methoxyphenyl)methyl]-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-7-ol
(S)-laudanine = 5-[((1S)-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-1-yl)methyl]-2-methoxyphenol
(R)-laudanine = 5-[((1R)-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-1-yl)methyl]-2-methoxyphenol
Systematic name: S-adenosyl-L-methionine:(R,S)-reticuline 7-O-methyltransferase
Comments: The enzyme from the plant Papaver somniferum (opium poppy) methylates (S)- and (R)-reticuline with equal efficiency and is involved in the biosynthesis of tetrahydrobenzylisoquinoline alkaloids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Ounaroon, A., Decker, G., Schmidt, J., Lottspeich, F. and Kutchan, T.M. (R,S)-Reticuline 7-O-methyltransferase and (R,S)-norcoclaurine 6-O-methyltransferase of Papaver somniferum - cDNA cloning and characterization of methyl transfer enzymes of alkaloid biosynthesis in opium poppy. Plant J. 36 (2003) 808–819. [DOI] [PMID: 14675446]
2.  Weid, M., Ziegler, J. and Kutchan, T.M. The roles of latex and the vascular bundle in morphine biosynthesis in the opium poppy, Papaver somniferum. Proc. Natl. Acad. Sci. USA 101 (2004) 13957–13962. [DOI] [PMID: 15353584]
[EC 2.1.1.291 created 2013]
 
 
EC 2.1.1.337     
Accepted name: reticuline N-methyltransferase
Reaction: (1) S-adenosyl-L-methionine + (S)-reticuline = S-adenosyl-L-homocysteine + (S)-tembetarine
(2) S-adenosyl-L-methionine + (S)-corytuberine = S-adenosyl-L-homocysteine + (S)-magnoflorine
For diagram of corytuberine and magnoflorine biosynthesis, click here and for diagram of tembetarine biosynthesis, click here
Glossary: (S)-reticuline = (1S)-1-(3-hydroxy-4-methoxybenzyl)-6-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinolin-7-ol
(S)-tembetarine = (1S)-1-(3-hydroxy-4-methoxybenzyl)-6-methoxy-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolin-7-ol
(S)-corytuberine = (6aS)-2,10-dimethoxy-6-methyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline-1,11-diol
(S)-magnoflorine = (6aS)-1,11-dihydroxy-2,10-dimethoxy-6,6-dimethyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinolinium
Other name(s): RNMT
Systematic name: S-adenosyl-L-methionine:(S)-reticuline N-methyltransferase
Comments: The enzyme from opium poppy (Papaver somniferum) can also methylate (R)-reticuline, tetrahydropapaverine, (S)-glaucine and (S)-bulbocapnine. It is involved in the biosynthesis of the quaternary benzylisoquinoline alkaloid magnoflorine.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Morris, J.S. and Facchini, P.J. Isolation and characterization of reticuline N-methyltransferase involved in biosynthesis of the aporphine alkaloid magnoflorine in opium poppy. J. Biol. Chem. 291 (2016) 23416–23427. [DOI] [PMID: 27634038]
[EC 2.1.1.337 created 2017]
 
 
EC 4.2.1.78     
Accepted name: (S)-norcoclaurine synthase
Reaction: 4-hydroxyphenylacetaldehyde + dopamine = (S)-norcoclaurine + H2O
For diagram of reaction, click here
Glossary: dopamine = 4-(2-aminoethyl)benzene-1,2-diol
Other name(s): (S)-norlaudanosoline synthase; 4-hydroxyphenylacetaldehyde hydro-lyase (adding dopamine)
Systematic name: 4-hydroxyphenylacetaldehyde hydro-lyase [adding dopamine; (S)-norcoclaurine-forming]
Comments: The reaction makes a six-membered ring by forming a bond between C-6 of the 3,4-dihydroxyphenyl group of the dopamine and C-1 of the aldehyde in the imine formed between the substrates. The product is the precursor of the benzylisoquinoline alkaloids in plants. The enzyme, formerly known as (S)-norlaudanosoline synthase, will also catalyse the reaction of 4-(2-aminoethyl)benzene-1,2-diol + (3,4-dihydroxyphenyl)acetaldehyde to form (S)-norlaudanosoline, but this alkaloid has not been found to occur in plants.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 79122-01-3
References:
1.  Stadler, R., Zenk, M.H. A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline. Liebigs Ann. Chem. (1990) 555–562.
2.  Stadler, R., Kutchan, T.M., Zenk, M.H. (S)-Norcoclaurine is the central intermediate in benzylisoquinoline alkaloid biosynthesis. Phytochemistry 28 (1989) 1083–1086.
3.  Samanani, N. and Facchini, P.J. Purification and characterization of norcoclaurine synthase. The first committed enzyme in benzylisoquinoline alkaloid biosynthesis in plants. J. Biol. Chem. 277 (2002) 33878–33883. [DOI] [PMID: 12107162]
[EC 4.2.1.78 created 1984, modified 1999]
 
 


Data © 2001–2022 IUBMB
Web site © 2005–2022 Andrew McDonald