Genome sequencing of Streptomyces malaysiensis DSM 4137 revealed the presence of four terpene cyclase genes, one of which was characterised as (+)-isoafricanol synthase. Its cyclisation mechanism was extensively studied using isotopically labelled precursors. Several enzymes with high homology that likely also function as (+)-isoafricanol synthases are encoded in a number of other genome sequenced streptomycetes.