Functional expression of the Aspergillus flavus
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- 作者：Yasuyo Seshime ; Praveen Rao Juvvadi ; Masafumi Tokuoka ; Yasuji Koyama ; Katsuhiko Kitamoto ; Yutaka Ebizuka ; Isao Fujii
- 关键词：Cyclopiazonic acid ; Aspergillus flavus ; Biosynthesis ; Polyketide synthase– ; nonribosomal peptide synthase (PKS– ; NRPS)
- 刊名：Bioorganic and Medicinal Chemistry Letters
- 出版年：2009
- 出版时间：15 June 2009
- 年：2009
- 卷：19
- 期：12
- 页码：3288-3292
- 全文大小：480 K
文摘
α-Cyclopiazonic acid (CPA) is an indole tetramic acid mycotoxin. Based on our identification of the polyketide synthase–nonribosomal peptide synthase (PKS–NRPS) hybrid gene cpaA involved in cyclopiazonic acid biosynthesis in Aspergillus fungi, we carried out heterologous expression of Aspergillus flavus cpaA under α-amylase promoter in Aspergillus oryzae and identified its sole product to be the CPA biosynthetic intermediate cyclo-acetoacetyl-l-tryptophan (cAATrp). This result rationalized that the PKS–NRPS hybrid enzyme CpaA catalyzes condensation of the diketide acetoacetyl-ACP formed by the PKS module and l-Trp activated by the NRPS module. This CpaA expression system provides us an ideal platform for PKS–NRPS functional analysis, such as adenylation domain selectivity and product releasing mechanism.