ID 2.5.1.115 DE homogentisate phytyltransferase. AN HPT. CA H(+) + homogentisate + phytyl diphosphate = 2-methyl-6-phytyl-1,4- CA benzene-1,4-diol + CO2 + diphosphate. CC -!- Involved in the biosynthesis of the vitamin E tocopherols. CC -!- While the enzyme from the cyanobacterium Synechocystis PCC 6803 has CC an appreciable activity with geranylgeranyl diphosphate CC (EC 2.5.1.116), the enzyme from the plant Arabidopsis thaliana has CC only a low activity with that substrate. CC -!- Formerly EC 2.5.1.n8. DR P73726, HGGT_SYNY3 ; Q8VWJ1, HPT1_ARATH ; B7FA90, HPT1_ORYSJ ; DR Q0D576, HPT2_ORYSJ ; //