All trans nonaprenyl diphosphate synthase (geranylgeranyl diphosphate specific)

All-trans-nonaprenyl diphosphate synthase (geranylgeranyl-diphosphate specific) (EC 2.5.1.85, nonaprenyl diphosphate synthase, solanesyl diphosphate synthase, At-SPS2, At-SPS1, SPS1, SPS2) is an enzyme with systematic name geranylgeranyl-diphosphate:isopentenyl-diphosphate transtransferase (adding 5 isopentenyl units). This enzyme catalyses the following chemical reaction

geranylgeranyl diphosphate + 5 isopentenyl diphosphate ⇌ 5 diphosphate + all-trans-nonaprenyl diphosphate

Geranylgeranyl diphosphate is preferred over farnesyl diphosphate as allylic substrate.