Key Laboratory of Marine Drugs, Ministry of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
Mar Drugs. 2013 Feb 6;11(2):466-88. doi: 10.3390/md11020466.
The indolocarbazole (ICZ) alkaloids have attracted much attention due to their unique structures and potential therapeutic applications. A series of ICZs were recently isolated and identified from a marine-derived actinomycete strain, Streptomyces sanyensis FMA. To elucidate the biosynthetic machinery associated with ICZs production in S. sanyensis FMA, PCR using degenerate primers was carried out to clone the FAD-dependent monooxygenase gene fragment for ICZ ring formation, which was used as a probe to isolate the 34.6-kb DNA region containing the spc gene cluster. Sequence analysis revealed genes for ICZ ring formation (spcO, D, P, C), sugar unit formation (spcA, B, E, K, J, I), glycosylation (spcN, G), methylation (spcMA, MB), as well as regulation (spcR). Their involvement in ICZ biosynthesis was confirmed by gene inactivation and heterologous expression in Streptomyces coelicolor M1152. This work represents the first cloning and characterization of an ICZ gene cluster isolated from a marine-derived actinomycete strain and would be helpful for thoroughly understanding the biosynthetic mechanism of ICZ glycosides.
吲哚咔唑（ICZ）生物碱由于其独特的结构和潜在的治疗应用而引起了广泛关注。最近从海洋来源放线菌菌株 Streptomyces sanyensis FMA 中分离并鉴定出一系列 ICZ。为了阐明与 S. sanyensis FMA 中 ICZ 生产相关的生物合成机制，使用简并引物进行 PCR 以克隆用于 ICZ 环形成的 FAD 依赖性单加氧酶基因片段，该片段用作探针以分离包含 spc 基因簇的 34.6-kb DNA 区域。序列分析揭示了用于 ICZ 环形成（spcO、D、P、C）、糖单元形成（spcA、B、E、K、J、I）、糖基化（spcN、G）、甲基化（spcMA、MB）以及调控（spcR）的基因。通过基因失活和在 Streptomyces coelicolor M1152 中的异源表达证实了它们在 ICZ 生物合成中的参与。这项工作代表了首次从海洋来源放线菌菌株中克隆和表征 ICZ 基因簇，这将有助于深入了解 ICZ 糖苷的生物合成机制。
