Diversity of the biosynthesis of the isoprene units.

This review covers the biosynthesis of the starter units of terpenoids, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) via the nonmevalonate pathway together with a new enzyme involved in the conversion of IPP and DMAPP, i.e type 2 IPP isomerase. The biosynthesis of terpenoids produced by actinomycetes is also reviewed. 117 references are cited.