Substrate specificity of thermostable farnesyl diphosphate synthase with alkyl group homologs of isopentenyl diphosphate.

3-Alkyl group homologs of isopentenyl diphosphate were examined for the reactivity as substrates of the thermostable farnesyl diphosphate (FPP) synthase of Bacillus stearothermophilus. Even 3-n-propyl- and 3-n-butyl-but-3-enyl diphosphates, which are hardly acceptable by animal FPP synthases, are accepted by this bacterial enzyme as substrates to react with dimethylallyl- and geranyl diphosphates, yielding 7-methyl-3-n-propylocta-2,6-dienyl- and 7,11-dimethyl-3-n-propyldodeca-2,6,10-trienyl diphosphate, respectively.