BIOSYNTHESIS OF ANTHRACYCLINE ANTIBIOTICS

该提案要求我们继续研究 蒽环类抗生素生物合成的生物化学和遗传学 为期五年。 在此期间，我们将 (i) 隔离并 研究所谓的“芳香族聚酮化合物”的特性 合酶”及其结构基因，(ii) 定义了遗传和 蒽环类抗生素生物合成的生化组织 途径，特别强调对 DNA、RNA 的调节 和蛋白质水平，以及（iii）探索表达的可能性 其他放线菌中的链霉菌基因并创造新的 通过基因工程生产蒽环类抗生素。 在此期间的主要项目将是研究 四烯霉素 C 以及由其生产的抗肿瘤抗生素 青色链霉菌。 我们将完成克隆 中医基因然后按标准解剖中医基因簇 技术个体中医基因。 将研究它们的结构 通过核苷酸测序、S1作图等方法 定位调节区域和转录/翻译 启动/停止站点。 此信息和北方的结果 杂交将用于识别转录单位 属于中医基因簇。 酶催化 TcmC芳香族聚酮化合物中间体的形成 通过将其基因插入其中，生物合成将被过量生产 合适的表达载体以促进其研究 物理和生化特性。 这样我们就可以建立 有关 TcmC 生物合成调控的信息 DNA、RNA 和蛋白质水平。 附属项目将涉及克隆基因 生产埃罗霉素（TcmC 的类似物）；使用中医 基因作为调控相关生化途径的基因的探针 在链霉菌中；在其他方面表达中医基因 放线菌；并探索建设的可能性 通过基因工程开发杂交蒽环类药物。

This proposal requests continuation of our study of the biochemistry and genetics of anthracycline antibiotic biosynthesis for a five year period. During this time we will (i) isolate and study the properties of the socalled " aromatic polyketide synthases" and their structural genes, (ii) define the genetic and biochemical organization of anthracycline antibiotic biosynthetic pathways with special emphasis on their regulation at DNA, RNA and protein levels, and (iii) explore the possibilities for expressing Streptomyces genes in other actinomycetes and creating new anthracycline antibiotics by genetic engineering. The major project during this period will be a study of tetracenomycin C, and antitumor antibiotic produced by Streptomyces glaucescens. We will complete the cloning of the tcm genes then dissect the tcm gene cluster by standard techniques individual tcm genes. Their structures will be studied by nucleotide sequencing, S1 mapping, and other methods to locate the regulatory regions and transcriptional/translational start/stop sites. This information and the results of Northern hybridizations will be used to identify the transcriptional units within the tcm gene cluster. The enzymes catalyzing the formation of the aromatic polyketide intermediates of TcmC biosythesis will be overproduced by inserting their genes in suitable expression vectors to facilitate the study of their physical and biochemical properties. In this way we will establish information about the regulation of TcmC biosynthesis at the DNA, RNA and protein levels. Subsidiary projects will involve cloning the genes for the production of elloramycin, an analog of TcmC; using the tcm genes as probes for genes governing related biochemical pathways in Streptomyces; expressing the tcm genes in other actinomycetes; and exploring the possibilities for the construction of hybrid anthracyclines by genetic engineering.