Solanesyl diphosphate

This enzyme [EC 2.5.1.11], also known as nonaprenyl-diphosphate synthase and solanesyl-diphosphate synthase, catalyzes the reaction of all-tra -octaprenyl diphosphate with isopentenyl diphosphate to produce all- ra 5-nonaprenyl diphosphate and pyrophosphate. The enzyme will also utilize geranyl diphosphate and di -trans-pxQny diphosphates of intermediate size as substrates, but it will not use dimethylallyl diphosphate. 

Rubber also contains almost entirely Z double bonds. Consistent with this fact is the finding that the prenyltransferases catalyzing formation of rubber promote loss of the pro-R proton rather than the pro-S proton of mevalonic acid (see Eq. 22-2). There appear to be two types of prenyltransferase in animal mitochondria giving rise to E and Z double bonds, respectively.64 In contrast, the rubber tree contains a 137-residue protein, the rubber elongation factor. This small protein binds to E prenyltransferases causing them to form Z double bonds.65 The bacterium Micrococcus hit cits synthesizes all E polyprenyl alcohol diphosphates up to the 0 5 nonaprenyl compound solanesyl diphosphate.66... 

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