Discovery and characterization of new natural products from uncultured bacteria

项目总结： 对具有生物活性的天然产物的研究一直是鉴定 具有独特细胞靶点的化合物，既用作治疗药物，最近在 化学遗传学的新兴领域，作为复杂生物系统的调节器。其中一个关键是 从环境样本的分子系统发育分析中得到的启示是，只有一小部分 环境中存在的部分细菌很容易培养。传统的方法用于 因此，发现新的天然产品不太可能提供获得绝大多数天然产品的途径 自然界中存在的产品。尚未培养的土壤微生物，因此也没有 经检验，生产有用的天然产品的数量至少比培养的产品多两个 到三个数量级。基于基因保守区的简并引物的聚合酶链式反应 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粘粒文库，以寻找生物合成途径 对新天然产品的生产进行编码。然后将使用异源表达来访问 由这些新基因簇编码的分子和由此产生的分子被筛选出生物活性 各种与人类疾病相关的屏幕。 相关性： 天然产物，即天然衍生的小型有机化合物，传统上一直是主要的 FDA批准的治疗药物的来源。未培养的细菌是最大的剩余细菌池之一 尚未对次生代谢物的产生进行检测的遗传多样性。这个 开发从功能上获取以前无法获得的天然产品的方法 未培养的细菌应该显著增加天然产品的数量和多样性，这些产品是 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.