46 菌類ポリケタイド生合成遺伝子のクローニングと発現(口頭発表の部)

概要

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Microbes produce a variety of polyketide compounds. Many of them are used as clinically important antibiotics or medicines. Gene cloning studies were carried out to investigate microbial polyketide biosynthesis at gene level. From Streptomyces galilaeus, aklavinone biosynthesis gene cluster was cloned and sequenced. ORF analysis revealed the presence of genes aknA, aknB, aknC, and aknD of which functions are assumed to be KR, KS, CLF, and ACP, respectively. The aknX gene located just upstream of aknB (KS) gene was expressed in E. coli and was found to code for anthrone oxygenase. AtX gene was cloned from Aspergillus terreus. The deduced amino acid sequence showed 62% homology with Penicillium patulum 6-methylsalicylic acid synthase. The atX gene was expressed in A. nidulans and production of 6-methylsalicylic acid was observed. This is the first example of successful expression of fungal PKS gene in heterologous host. The genomic DNA and cDNA for dihydrogeodin oxidase (DHGO), a specific phenol oxidative coupling enzyme, were also cloned from A. terreus. Sequencing analysis revealed the presence of six introns in the DHGO genomic DNA and four copper binding motifs are found in the DHGO deduced amino acid sequence. The successful expression as active blue copper enzyme was accomplished in A. nidulans transformant harboring the cloned gene.
天然有機化合物討論会の論文
1995-09-01