This fungal enzyme, isolated from Magnaporthe oryzae, is an non-ribosomal peptide synthetase (NRPS)-polyketide synthase (PKS) hybrid protein that consists of condensation (C), adenylation (A) and peptidyl-carrier protein (PCP) domains in the NRPS portion and a ketosynthase (KS) domain in the PKS portion. ATP is required for activation of isoleucine, which is then condensed with acetoacetyl-CoA. Cyclization and release from the enzyme are catalysed by the KS domain.