New insights into pradimicin biosynthesis revealed by two O-methyltransferases

BIOORGANIC & MEDICINAL CHEMISTRY LETTERS

卷:27

Article

Xu, Fuchao¹  Napan, Kandy¹  Zhang, Shuwei¹  Gladwin, Tyler¹  Takemoto, Jon²  Zhan, Jixun¹ 

[1] Utah State Univ, Dept Biol Engn, 4105 Old Main Hill, Logan, UT 84322 USA

[2] Utah State Univ, Dept Biol, 5305 Old Main Hill, Logan, UT 84322 USA

关键词: Pradimicin;    O-Methyltransferase;    Demethoxylation;    Gene disruption;    Heterologous expression;   

DOI  :  10.1016/j.bmcl.2017.05.068

来源: Elsevier

【 摘 要 】

Pradimicins are a group of antiviral and antifungal natural products from Actinomadura hibisca. Two putative O-methyltransferase genes, pdmF and pdmT, are present in the pradimicin biosynthetic gene cluster. However, there is only one methoxy group (11-OCH3) in pradimicins. Through heterologous expression and in vitro reactions with various substrates, PdmF was characterized as the C-11 O-methyltransferase with a relatively broad substrate specificity. To probe the role of PdmT in pradimicin biosynthesis, the corresponding gene was disrupted through homologous recombination, leading to the production of pradimicinone II. This enzyme was then expressed in Escherichia coli with an N-terminal His(6) tag and purified by Ni-NTA chromatography. Reaction of pradimicinone II with PdmT generated 7-O-methylpradimicinone II, confirming that this enzyme is a C-7O-methyltransferase. Characterization of PdmT suggests a novel pathway that leads to the flip of 7-OH to C-14 in pradimicin biosynthesis. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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