| Synonyms |
cePAH, DicPAH, EC 1.14.3.1, EC 1.99.1.2, HPAH, L-phenylalanine 4-hydroxylase, oxygenase, phenylalanine 4-mono-, P4H, PAH, PheH, phenylalaninase, phenylalanine 4-hydroxylase, phenylalanine hydroxylase, phenylalanine monooxygenase, PheOH, phhA |
| Comments |
The active centre contains mononuclear iron(II). The reaction involves an arene oxide that rearranges to give the phenolic hydroxy group. This results in the hydrogen at C-4 migrating to C-3 and in part being retained. This process is known as the NIH-shift. The 4a-hydroxytetrahydrobiopterin formed can dehydrate to 6,7-dihydrobiopterin, both spontaneously and by the action of EC 4.2.1.96, 4a-hydroxytetrahydrobiopterin dehydratase. The 6,7-dihydrobiopterin can be enzymically reduced back to tetrahydrobiopterin, by EC 1.5.1.34, 6,7-dihydropteridine reductase, or slowly rearranges into the more stable compound 7,8-dihydrobiopterin. |
