Fig. 2.

General architecture of iterative type I PKS. Aspergillus PKSs minimally contain ketosynthase (KS), acyl transferase (AT) and acyl carrier protein (ACP) domains. They can be classified into three different groups. I) Non Reduced PKS e.g. pksA from A. flavus (pksL from A. parasiticus) responsible for Aflatoxin synthesis contain SAT, KS, AT, PT, ACP, TE domains. A. fumigatus producing 1,3,6,8-tetrahydroxynapthalene (THN) and pksST from Aspergillus nidulans contain additional ACP domain. II) Partially reduced PKS e.g. 6-MSA (6-methylsalicylic acid) from A. niger secreting antibiotic yanuthone D contains KS, AT, Dh, KR and ACP. III) Highly reducing PKS e.g. lovB (lov astatin nanaketide synthease) and lovF, are involved in the formation of lovastatin in A. terreus. Both PKS gene have KS, AT, DH, CMeT, ER, KR and ACP domains while for lovB CON domain is also present