A clone encoding farnesyl diphosphate synthase (FPPS) was obtained by PCR from a cDNA library made from young leaves of Artemisia annua. A cDNA clone encoding the tobacco epi-aristolochene synthase (eAS) was kindly supplied by J. Chappell (University of Kentucky, Lexington, KY, USA). Two fusions were constructed, . FPPS/ eAS and eAS/FPPS. The stop codon of the N-terminal enzyme was removed and replaced by a short peptide (Gly-SerGly) to introduce a linker between the two ORFs. These two fusions and the two single cDNA clones were separately introduced into a bacterial expression vector (pET32). Escherichia coli was transformed with the.
