Geranylgeranyl diphosphate synthase in fission yeast is a heteromer of farnesyl diphosphate synthase (FPS), Fps1, and an FPS-like protein, Spo9, essential for sporulation.
Ye Y, Fujii M, Hirata A, Kawamukai M, Shimoda C, Nakamura T. Mol Biol Cell. 2007 Sep; 18(9):3568-81. Epub 2007 Jun 27.