Description: Tyrosine is produced in cells by hydroxylating (via phenylalanine hydroxylase) the essential amino acid phenylalanine. Half of the phenylalanine required goes into the production of tyrosine; if the diet is rich in tyrosine itself, the requirements for phenylalanine are reduced by about 50%. Phenylalanine hydroxylase is a mixed-function oxygenase: one atom of oxygen is incorporated into water and the other into the hydroxyl of tyrosine. The reductant is the tetrahydrofolate- related cofactor tetrahydrobiopterin, which is maintained in the reduced state by the NADH-dependent enzyme dihydropteridine reductase (DHPR). The catabolism of tyrosine starts with an \u03b1-ketoglutarate dependent transamination through the tyrosine transaminase, which generates p-hydroxyphenylpyruvate. The next oxidation step is catalyzed by p-hydroxylphenylpyruvate- dioxygenase and generates homogentisate (2,5-dihydroxyphenyl-1-acetate). In order to split the aromatic ring of homogentisate, a further dioxygenase, homogentistate-oxygenase is required. Through this reaction, maleylacetoacetate is created. Fumarylacetate is then generated by maleylacetoacetate-cis-trans-isomerase through rotation of the carboxyl group created from the hydroxyl group via oxidation. This cis-trans-isomerase contains glutathione as a coenzyme. Fumarylacetoacetate is finally split into acetoactate and fumarate via fumarylacetoacetate-hydrolase through the addition of a water molecule. Thereby fumarate (also a metabolite of the citric acid cycle) and acetoacetate (3-ketobutyroate) are liberated. Acetoacetate is a ketone body, which is activated with succinyl-CoA, and thereafter it can be converted into acetyl-CoA which in turn can be oxidized by the citric acid cycle or be used for fatty acid synthesis. Source: Pathman

Related BMRB Molecules

• 4-Chlorophenylacetate
• DL-3,4-Dihydroxymandelic Acid
• 3,4-Dihydroxyphenylacetic Acid
• 3,5-Diiodo-L-Tyrosine
• Dopamine
• Fumaric Acid
• Homogentisic Acid
• Homovanillic Acid
• Hydroquinone
• 4-Hydroxy-3-Methoxymandelic Acid
• 3-Hydroxyphenylacetic Acid
• 4-Hydroxyphenylacetic Acid
• 3-Iodo-L-Tyrosine
• 3-Methoxytyramine
• Phenol
• Pyruvic Acid
• Rosmarinic Acid
• Succinic Acid
• L-Thyroxine
• Tyramine
• L-Tyrosine

For complete information about pathway, see KEGG [map00350]