What is "trans-octaprenyltranstransferase"

In enzymology, a trans-octaprenyltranstransferase is an enzyme that catalyzes the chemical reaction

all-trans-octaprenyl diphosphate + isopentenyl diphosphate $\rightleftharpoons$ diphosphate + all-trans-nonaprenyl diphosphate

Thus, the 2 substrates of this enzyme are all-trans-octaprenyl diphosphate and isopentenyl diphosphate, whereas its two products are diphosphate and all-trans-nonaprenyl diphosphate.

This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is (E)-octaprenyl-diphosphate:isopentenyl-diphosphate octaprenyltranstransferase. Other names in common use include all-trans-nonaprenyl-diphosphate synthase, solanesyl-diphosphate synthase, solanesyl pyrophosphate synthetase, SPP synthase, nonaprenyl pyrophosphate synthetase, polyprenylpyrophosphate synthetase, terpenoidallyltransferase, terpenyl pyrophosphate synthetase, trans-octaprenyltranstransferase, and trans-prenyltransferase. This enzyme participates in biosynthesis of steroids.