香港正版六六宝典

【10月14日】LMB学术报告_1.A Strategy to Overexpress a Large Biosynthetic Gene Cluster in Streptomyces Species _2.Natural Products 2.0: From Genome to Drug

  【报告题目1A Strategy to Overexpress a Large Biosynthetic Gene Cluster in Streptomyces Species 

  Prof. Eung-Soo KimInha University, South Korea 

  【报告题目2Natural Products 2.0: From Genome to Drug 

  高江涛教授(福建农林大学)   

    间:20151014 15:30 

    点:标本楼6楼学术报告厅 

  主持人:鞠建华研究员 

 

报告1摘要 

    Direct cloning combined with heterologous expression of a secondary metabolite biosynthetic gene cluster has become a useful strategy for production improvement and pathway modification of potentially valuable natural products present at minute quantities in original isolates of actinomycetes. However, precise cloning and efficient overexpression of an entire biosynthetic gene cluster remains challenging due to the ineffectiveness of current genetic systems in manipulating large-sized gene clusters for heterologous as well as homologous expression. Here, a versatile Escherichia coli-Streptomyces shuttle bacterial artificial chromosomal (BAC) conjugation vector, pSBAC, was used along with a cluster tandem integration approach to carry out homologous and heterologous overexpression of an 80-kb biosynthetic pathway gene cluster of an immunosuppressant, tautomycetin (TMC). Unique XbaI restriction sites were precisely inserted at both border regions of the TMC biosynthetic gene cluster within the chromosome of TMC-producing Streptomyces sp. CK4412, followed by site-specific recombination of pSBAC into the flanking region of the TMC gene cluster. The entire TMC gene cluster was then rescued as a single giant recombinant pSBAC by XbaI digestion of the chromosomal DNA as well as subsequent self-ligation. The recombinant pSBAC construct in E. coli was directly conjugated into model Streptomyces strains, resulting in rapid and enhanced TMC production. Moreover, introduction of the TMC cluster-containing pSBAC into wild-type Streptomyces sp. CK4412 resulted in a chromosomal tandem repeat of the entire TMC cluster with 14-fold enhanced TMC productivities. This strategy can be employed to develop a custom overexpression scheme of entire metabolite pathway clusters present in actinomycetes. 

报告人1简介 

    Eung-Soo Kim教授,1994年于美国明尼苏达州大学取得微生物学及微生物技术博士学位,1997年在斯坦福大学完成博士后研究。目前担任SIMB编辑部委员,KMB秘书长,MSK生物技术部主席,ISBA组织委员会委员。主要研究领域是微生物技术:放线菌分子生物技术。更多信息可以浏览网站(http://actino.inha.ac.kr/) 

 

报告2摘要 

    Although natural products have been a particularly rich source of human medicines, activity-based or chemistry-based screening results in a very high rate of rediscovery of known molecules. Based on the large number of natural product biosynthetic genes in microbial genomes, many have proposed “genome mining” as an alternative approach for discovery efforts; however, this idea has yet to be performed experimentally on a large scale. Here, we demonstrate the feasibility of large-scale, high-throughput genome mining by screening a collection of over 10,000 actinomycetes for the genetic potential to make phosphonic acids, a class of natural products with diverse and useful bioactivities. Genome sequencing identified a diverse collection of phosphonate biosynthetic gene clusters within 278 strains. Characterization of strains within five of these groups resulted in the discovery of 11 previously undescribed phosphonic acid natural products. Analysis of the genome sequences from the remaining strains suggests that the majority of the phosphonate biosynthetic repertoire of Actinobacteria has been captured at the gene level. This dereplicated strain collection now provides a reservoir of numerous, as yet undiscovered, phosphonate natural products. 

However, there are two big problems to be solved for this platform. First, it is very difficult to identify and isolate this kind of compounds from Nature as a consequence of their low quantity and high hydrophilicity. Here we successfully developed an isotope labeling strategy for identifying phosphonate natural products based on our recent finding that the enzyme DhpI has broad substrate specificity and can methylate a variety of C-P natural products. Second, many of these gene clusters are silent or cryptic. Here we successfully apply a plug-and-play synthetic biology strategy to activate cryptic phosphonic acid biosynthetic gene clusters. 

报告人2简介 

    高江涛, 博士生导师, 福建农林大学金山学者, 福建省闽江学者特聘教授。2001年毕业于中国海洋大学并获得学士学位, 2005年毕业于香港正版六六宝典海洋研究所并获得硕士学位, 2010年毕业于美国密西西比大学药学院并获得药学博士, 博士毕业后进入美国伊利诺伊大学厄本那香槟分校从事博士后研究(导师:Prof. Wilfred van der Donk,美国文理科学院院士,HHMI研究员)。长期从事后基因组时代的微生物天然产物药物的研发, 其多项相关研究成果已在Chemical Reviews, Angewandte Chemie International Edition,  PNAS Science, ACS Chemical Biology, Journal of Natural Products 等国际权威杂志发表。 


附件下载: