Tyrosine N-monooxygenase
| Tyrosine N-monooxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 1.14.14.36 | ||||||||
| CAS no. | 159447-19-5 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Tyrosine N-monooxygenase (EC 1.14.14.36, tyrosine N-hydroxylase, CYP79A1) is an enzyme with systematic name L-tyrosine,NADPH:oxygen oxidoreductase (N-hydroxylating).[1][2] This enzyme catalyses a sequence of chemical reactions starting from the amino acid L-tyrosine.[3]
The first is an oxidation using molecular oxygen as oxidant and gives N-hydroxytyrosine:
The enzyme is a cytochrome P450 type of hemoprotein which contains reduced nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor.[4]
Another similar oxidation step leads to N,N-dihydroxy-L-tyrosine, which loses carbon dioxide and water to give (E)-(4-hydroxyphenyl)acetaldehyde oxime as the final product of the enzyme.[5][6]
N-hydroxytyrosine
O2 + H+
H2O
N,N-dihydroxy-L-tyrosine
CO2 + H2O
-(4-hydroxyphenyl)acetaldehyde_oxime.svg.png)
(E)-(4-hydroxyphenyl)acetaldehyde oxime
In plants such as sorghum, the product goes on to form the cyanogenic glycoside, dhurrin after the (E) isomer of the oxime is converted to its (Z) form and further transformed.[6][7][8]
References
- ↑ Halkier BA, Møller BL (December 1990). "The biosynthesis of cyanogenic glucosides in higher plants. Identification of three hydroxylation steps in the biosynthesis of dhurrin in Sorghum bicolor (L.) Moench and the involvement of 1-ACI-nitro-2-(p-hydroxyphenyl)ethane as an intermediate". The Journal of Biological Chemistry. 265 (34): 21114–21. doi:10.1016/S0021-9258(17)45334-8. PMID 2250015.
- ↑ Bak S, Olsen CE, Halkier BA, Møller BL (August 2000). "Transgenic tobacco and Arabidopsis plants expressing the two multifunctional sorghum cytochrome P450 enzymes, CYP79A1 and CYP71E1, are cyanogenic and accumulate metabolites derived from intermediates in Dhurrin biosynthesis". Plant Physiology. 123 (4): 1437–48. doi:10.1104/pp.123.4.1437. PMC 59100. PMID 10938360.
- ↑ Enzyme 1.14.14.36 at KEGG Pathway Database.
- ↑ Sibbesen O, Koch B, Halkier BA, Møller BL (February 1995). "Cytochrome P-450TYR is a multifunctional heme-thiolate enzyme catalyzing the conversion of L-tyrosine to p-hydroxyphenylacetaldehyde oxime in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench". The Journal of Biological Chemistry. 270 (8): 3506–11. doi:10.1074/jbc.270.8.3506. PMID 7876084.
- ↑ Nielsen JS, Møller BL (April 2000). "Cloning and expression of cytochrome P450 enzymes catalyzing the conversion of tyrosine to p-hydroxyphenylacetaldoxime in the biosynthesis of cyanogenic glucosides in Triglochin maritima". Plant Physiology. 122 (4): 1311–21. doi:10.1104/pp.122.4.1311. PMC 58967. PMID 10759528.
- 1 2 Clausen, Mette; Kannangara, Rubini M.; Olsen, Carl E.; et al. (2015). "The bifurcation of the cyanogenic glucoside and glucosinolate biosynthetic pathways". The Plant Journal. 84 (3): 558–573. doi:10.1111/tpj.13023. PMID 26361733.
- ↑ Busk PK, Møller BL (July 2002). "Dhurrin synthesis in sorghum is regulated at the transcriptional level and induced by nitrogen fertilization in older plants". Plant Physiology. 129 (3): 1222–31. doi:10.1104/pp.000687. PMC 166516. PMID 12114576.
- ↑ Kristensen C, Morant M, Olsen CE, Ekstrøm CT, Galbraith DW, Møller BL, Bak S (February 2005). "Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome". Proceedings of the National Academy of Sciences of the United States of America. 102 (5): 1779–84. Bibcode:2005PNAS..102.1779K. doi:10.1073/pnas.0409233102. PMC 545087. PMID 15665094.
External links
- Tyrosine+N-monooxygenase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
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