著者
Fujii Isao Mori Yuichiro Watanabe Akira KUBO Yasuyuki TSUJI Gento EBIZUKA Yutaka
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.63, no.8, pp.1445-1452, 1999-08-23
参考文献数
33
被引用文献数
9 80

The Colletotrichum lagenarium PKS1 gene was expressed in the heterologous fungal host, Aspergillus oryzae, under the starch-inducible α-amylase promoter to identify the direct product of polyketide synthase (PKS) encoded by the PKS1 gene. The main compound produced by an A.oryzae transformant was isolated and characterized to be 1,3,6,8-tetrahydroxynaphthalene (T4HN) as its tetraacetate. Since the PKS1 gene was cloned from C.lagenarium to complement the nonmelanizing albinio mutant, T4HN was assumed to be an initial biosynthetic intermediate, and thus the product of the PKS reaction, but had not been isolated from the fungus. The production of T4HN by the PKS1 transformant unambiguously identified the gene to encode a PKS of pentaketide T4HN. In addition, tetraketide orsellinic acid and pentaketide isocoumarin were isolated, the latter being derived from a pentaketide monocyclic carboxylic acid, as by-products of the PKS1 PKS reaction. Production of the pentaketide carboxylic acid provided insights into the mechanism for the PKS1 polyketide synthase reaction to form T4HN.