all-trans-octaprenyl-diphosphate synthase (EC 2.5.1.90)
all-trans-octaprenyl-diphosphate synthase
EC Number: 2.5.1.90
Reaction: (2E,6E)-farnesyl diphosphate + 5 isopentenyl diphosphate = 5 diphosphate + all-trans-octaprenyl diphosphate
Systematic name: (2E,6E)-farnesyl-diphosphate:isopentenyl-diphosphate farnesyltranstransferase (adding 5 isopentenyl units)
Other names: octaprenyl-diphosphate synthase; octaprenyl pyrophosphate synthetase; polyprenylpyrophosphate synthetase; terpenoidallyltransferase; terpenyl pyrophosphate synthetase; trans-heptaprenyltranstransferase; trans-prenyltransferase
Comments: This enzyme catalyses the condensation reactions resulting in the formation of all-trans-octaprenyl diphosphate, the isoprenoid side chain of ubiquinone-8 and menaquinone-8. The enzyme adds five isopentenyl diphosphate molecules sequentially to farnesyl diphosphate with trans stereochemistry