Elucidation of the Kijanimicin Gene Cluster: Insights into the Biosynthesis of Spirotetronate Antibiotics and Nitrosugars
作者:Hua Zhang、Jess A. White-Phillip、Charles E. Melançon、Hyung-jin Kwon、Wei-luen Yu、Hung-wen Liu
DOI:10.1021/ja0744854
日期:2007.11.28
formation of TDP-l-digitoxose, one of the two sugar donors used in construction of kijanimicin, was elucidated through biochemical analysis of four enzymes encoded in the gene cluster. Sequence analysis indicates that the aglycone kijanolide is formed by the combined action of a modular Type-I polyketide synthase, a conserved set of enzymes involved in formation, attachment, and intramolecular cyclization of
由放线菌 Actinomadura kijaniata 产生的抗生素 kijanimicin 具有广泛的生物活性以及许多有趣的生物合成特征。为了了解其形成的分子基础并开发此类化合物的组合生物合成系统,鉴定、克隆和测序了含有 kijanimicin 生物合成位点的 A. kijaniata 染色体的 107.6 kb 片段。通过对基因簇中编码的四种酶的生化分析,阐明了形成 TDP-1-洋地黄毒苷(用于构建 kijanimicin 的两个糖供体之一)的完整途径。序列分析表明,苷元kijanolide 是由模块化I 型聚酮化合物合酶的联合作用形成的,这是一组参与形成、附着、甘油酸衍生的三碳单元的分子内环化,形成螺环膦酸盐部分的核心。参与不寻常脱氧糖 d-kijanose [2,3,4,6-tetradeoxy-4-(methylcarbamyl)-3-C-methyl-3-nitro-d-xylo-hexopyranose]