ID   1.14.16.1
DE   Phenylalanine 4-monooxygenase.
AN   PAH.
AN   Phenylalaninase.
AN   Phenylalanine 4-hydroxylase.
AN   Phenylalanine hydroxylase.
CA   L-phenylalanine + tetrahydrobiopterin + O(2) = L-tyrosine +
CA   4a-hydroxytetrahydrobiopterin.
CF   Iron.
CC   -!- The reaction involves an arene oxide which rearranges to give the
CC       phenolic hydroxy group.
CC   -!- This results in the hydrogen at C-4 migrating to C-3 and in part
CC       being retained, a process known as the NIH-shift.
CC   -!- The 4a-hydroxytetrahydrobiopterin formed can dehydrate to 6,7-
CC       dihydrobiopterin, both spontaneously and by the action of
CC       EC 4.2.1.96.
CC   -!- The 6,7-dihydrobiopterin can be enzymically reduced back to
CC       tetrahydrobiopterin, by EC 1.5.1.34, or slowly rearranges into the
CC       more stable compound 7,8-dihydrobiopterin.
CC   -!- Formerly EC 1.14.3.1 and EC 1.99.1.2.
PR   PROSITE; PDOC00316;
DR   Q2KIH7, PH4H_BOVIN ;  P90925, PH4H_CAEEL ;  Q9A7V7, PH4H_CAUCR ;
DR   P30967, PH4H_CHRVO ;  Q54XS1, PH4H_DICDI ;  P17276, PH4H_DROME ;
DR   P00439, PH4H_HUMAN ;  P16331, PH4H_MOUSE ;  P43334, PH4H_PSEAE ;
DR   Q8XU39, PH4H_RALSO ;  P04176, PH4H_RAT   ;  Q98D72, PH4H_RHILO ;
DR   Q9KLB8, PH4H_VIBCH ;
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