Cloning and Functional Analysis of Fungal Polyketide Synthase Gene from Marine Aspergillus glaucus

It is critical to identify the polyketide synthase (PKS) gene cluster to clarify the biosynthetic mechanism of antitumor polyketide aspergiolide A, which was deduced to be catalyzed non reduced PKS (NR PKS) from marine Aspergillus glaucus. In this study, a NR PKS nucleotide sequence was first obtained using the LC primers. A full sequence of its gene clusters (22.8 kb) was harvested by genome walking, which contains 7 ORFs by BLAST analysis. Among them, a NR PKS gene with full length of 8 451 bp was identified by BLAST and designated as Agpks1. The AgPks1 showed high homology to Aspergillus fumigatus PksP and Aspergillus niger Alb1. This work provides enlightenment for analyzing the functions of Agpks1 in biosynthetic mechanism of aspergiolide A or other polyketides produced by Aspergillus glaucus.