Discovery and characterization of new natural products from uncultured bacteria

项目摘要： 生物活性天然产物的研究一直是鉴定 具有独特的细胞靶点的化合物，其既可用作治疗剂， 化学遗传学的新兴领域，作为复杂生物系统的调节剂。的一个关键 从环境样本的分子系统发育分析中得到的启示是， 存在于环境中的细菌的一部分容易培养。传统方法用于 因此，新的天然产品的发现不太可能提供对绝大多数天然产品的获取。 自然界中存在的产品。土壤微生物还没有被培养，因此没有被 被检测为生产有用的天然产品的数量超过了他们的培养同行至少两个 到三个数量级。基于基因保守区的简并引物PCR 已知参与天然产物的生物合成和高通量测序， 建议筛选直接从土壤中提取的DNA的粘粒文库的生物合成途径， 编码新的天然产物的生产。然后，将使用heterocycle表达式访问 由这些新基因簇编码的分子和由此产生的分子筛选生物活性， 各种人类疾病相关的屏幕。 相关性： 天然产物，天然衍生的小有机化合物，传统上是主要的有机化合物之一。 FDA批准的治疗药物的来源。未培养的细菌是最大的剩余池之一， 尚未对次级代谢产物的产生进行检测的遗传多样性。的 开发方法，以功能性地获得以前无法获得的天然产品， 未培养的细菌应该显着增加天然产物的数量和多样性， 可作为生物过程和治疗剂的探针进行测试。

Project Summary: The study of biologically active natural products has been a very effective gateway to the identification of compounds with unique cellular targets that have been useful both as therapeutics and,more recently in the emerging field of chemical genetics, as modulators of complex biological systems. One of the key revelations to come from molecular phylogenetic analyses of environmental samples is that only a small fraction of bacteria present in the environment is easily cultured. Traditional approaches used for the discovery of new natural products are therefore unlikely to provide access to the vast majority of natural products that exist in nature. Soil microbes that have not yet been cultured and as a result have not been examined for the production of useful natural products outnumber their cultured counterparts by at least two to three orders of magnitude. Using PCR with degenerate primers based on conserved regions in genes known to be involved in the biosynthesis of natural products and high throughput sequencing we are proposing to screen cosmid libraries of DNA extracted directly from soil for biosynthetic pathways that encode the production of new natural products. Heterologous expression will then be used to access the molecules encoded by these new gene clusters and the resulting molecules screened for biological activity in a variety of human disease related screens. Relevance: Natural products, naturally derived small organic compounds, have traditionally been one of the major sources of FDA approved therapeutics. Uncultured bacteria are one of the largest remaining pools of genetic diversity that have not yet been examined for the production of secondary metabolites. The development of methods to functionally access the previously inaccessible natural products produced by uncultured bacteria should significantly increase the number and diversity of natural products that are available to test as probes of biological processes and therapeutic agents.