Institute of Microbiology AS CR, Prague, Czech Republic.
J Appl Microbiol. 2011 Nov;111(5):1116-28. doi: 10.1111/j.1365-2672.2011.05132.x. Epub 2011 Sep 8.
Production of minor asukamycin congeners and its new derivatives by combination of targeted genetic manipulations with specific precursor feeding in the producer of asukamycin, Streptomyces nodosus ssp. asukaensis.
Structural variations of manumycins lie only in the diverse initiation of the 'upper' polyketide chain. Inactivation of the gene involved in the biosynthesis of cyclohexanecarboxylic acid (CHC) turned off the production of asukamycin in the mutant strain and allowed an increased production of other manumycins with the branched end of the upper chain. The ratio of produced metabolites was further affected by specific precursor feeding. Precursor-directed biosynthesis of a new asukamycin analogue (asukamycin I, 28%) with linear initiation of the upper chain was achieved by feeding norleucine to the mutant strain. Another asukamycin analogue with the unbranched upper chain (asukamycin H, 14%) was formed by the CHC-deficient strain expressing a heterologous gene putatively involved in the formation of the n-butyryl-CoA starter unit of manumycin A.
Combination of the described techniques proved to be an efficient tool for the biosynthesis of minor or novel manumycins.
Production of two novel asukamycin derivatives, asukamycins H and I, was achieved. Variations appeared in the upper polyketide chain, the major determinant of enzyme-inhibitory features of manumycins, affecting their cancerostatic or anti-inflammatory features.
通过靶向基因操作与特定前体喂养相结合，在阿苏卡霉素产生菌诺斯链霉菌亚种阿苏卡ensis 中生产阿苏卡霉素的同系物及其新衍生物。
曼努霉素的结构差异仅在于“上部”聚酮链的不同起始。参与环己烷羧酸（CHC）生物合成的基因失活使突变株中阿苏卡霉素的产生关闭，并允许具有上部链分支末端的其他曼努霉素的产量增加。产生的代谢物的比例通过特定的前体喂养进一步受到影响。通过向突变株中添加正亮氨酸，实现了新型阿苏卡霉素类似物（阿苏卡霉素 I，28%）的前体定向生物合成，其具有线性起始的上部链。另一种具有无分支上部链的阿苏卡霉素类似物（阿苏卡霉素 H，14%）由表达异源基因的 CHC 缺陷菌株形成，该基因推测参与曼努霉素 A 的 n-丁酰基-CoA 起始单元的形成。
所描述的技术组合被证明是生产次要或新型曼努霉素的有效工具。
生产了两种新型阿苏卡霉素衍生物，阿苏卡霉素 H 和 I。在上部聚酮链中出现了变异，这是曼努霉素抑制特征的主要决定因素，影响了它们的抗癌或抗炎特征。
