Escudero Leticia, Al-Refai Mahmoud, Nieto Cristina, Laatsch Hartmut, Malpartida Francisco, Seco Elena M
Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
Department of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077, Göttingen, Germany.
PLoS One. 2015 Aug 18;10(8):e0135891. doi: 10.1371/journal.pone.0135891. eCollection 2015.
The rimJ gene, which codes for a crotonyl-CoA carboxylase/reductase, lies within the biosynthetic gene cluster for two polyketides belonging to the polyene macrolide group (CE-108 and rimocidin) produced by Streptomyces diastaticus var. 108. Disruption of rimJ by insertional inactivation gave rise to a recombinant strain overproducing new polyene derivatives besides the parental CE-108 (2a) and rimocidin (4a). The structure elucidation of one of them, CE-108D (3a), confirmed the incorporation of an alternative extender unit for elongation step 13. Other compounds were also overproduced in the fermentation broth of rimJ disruptant. The new compounds are in vivo substrates for the previously described polyene carboxamide synthase PcsA. The rimJ disruptant strain, constitutively expressing the pcsA gene, allowed the overproduction of CE-108E (3b), the corresponding carboxamide derivative of CE-108D (3a), with improved pharmacological properties.
rimJ基因编码巴豆酰辅酶A羧化酶/还原酶,位于淀粉酶链霉菌变种108产生的属于多烯大环内酯类的两种聚酮化合物(CE - 108和龟裂杀菌素)的生物合成基因簇内。通过插入失活破坏rimJ会产生一个重组菌株,除了亲本的CE - 108(2a)和龟裂杀菌素(4a)外,该菌株还过量产生新的多烯衍生物。其中一种化合物CE - 108D(3a)的结构解析证实了在延伸步骤13中引入了替代延伸单元。rimJ破坏株的发酵液中也过量产生了其他化合物。这些新化合物是先前描述的多烯羧酰胺合酶PcsA的体内底物。组成型表达pcsA基因的rimJ破坏株能够过量产生CE - 108E(3b),即CE - 108D(3a)的相应羧酰胺衍生物,其药理特性有所改善。