Specific production of γ-polypodatetraene or 17-isodammara-20(21),24-diene by squalene–hopene cyclase mutant

Amino acids lining the catalytic cavity of squalene–hopene cyclase of Alicyclobacillus acidocaldarius were mutated to investigate their catalytic functions. Mutagenesis of Leu607 to Lys in the central part of the cavity resulted in the production of the bicyclic γ-polypodatetraene (1) as main product, while the mutation of Phe605 to Lys near the deprotonation site of the cavity led mainly to the formation of tetracyclic 17-isodammara-20(21),24-diene (2).