SILENT GENES FOR STREPTOMYCIN SYNTHESIS IN STREPTOMYCES

最近，人们越来越迫切地需要开发持久的疗法。 已经抵抗了传统抗生素的几种病理性疾病。这 除其他外，已经引起了更大的需要，以制定更有效的 抗生素和抗肿瘤药物。巧合的是，这发生在一个 当越来越多的证据积累起来，表明 链霉菌中次级代谢物沉默基因的分布 以及利用这些基因生产新的 抗生素。其中一组沉默的基因包括 放线菌素途径中的关键酶--吩恶嗪酮合成酶 D在链霉菌中的生物合成。这位申请人 认识到放线菌素D作为抗肿瘤药物的临床应用有限 并建议检查PHS基因的沉默同源物。 链霉菌，作为基因修饰的潜在候选者 放线菌素生物合成途径的临床应用&L类似物 这种抗生素。 因此，拟议研究的具体目标包括：(1) 该酶沉默基因(S)的克隆与鉴定 天蓝色链霉菌的吩恶嗪酮合成酶(PHS)，以及 蓝链霉菌；(Ii)阐明其作用机制 基因的加密和激活(S)；(Iii)分离 推测途径的整个基因簇；以及(Iv)探索， 通过分子干预，这些沉默的潜在作用 放线菌素或其他抗肿瘤药物生产中的等位基因。 预计拟议的实验将产生显著的 将对继续审查有用的信息量 该细菌属的成员，用于合成细菌的沉默途径 新型抗生素。该项目还将提供一个急需的 应聘者培养本科生的机会 在分子生物学和微生物遗传学领域。

Recently, there has been a growing urgency to develop lasting therapies for several pathologies that have withstood traditional antibiotics. This has given rise to, among others, a greater need to develop more effective antibiotics and anti-neoplastic agents. Coincidentally, this comes at a time when a mounting evidence is accumulating indicating the widespread distribution in Streptomycetes of silent genes for secondary metabolites, and the potential to harness such genes for the production of novel antibiotics. One such group of silent genes consists of those for phenoxazinone synthase (PHS), a key enzyme in the pathway of actinomycin D biosynthesis in Streptomyces antibiotics of silent. This applicant realizes the limited clinical use of actinomycin D as an antineoplastic agent, and proposes to examine the silent homologs of the PHS gene in Streptomycetes, as potential candidates for a genetic modification of the actinomycin biosynthetic pathway to produce clinically more use&l analogs of this antibiotic. The specific aims of the proposed research will therefore include: (i) cloning and characterizing the silent gene(s) for the enzyme phenoxazinone synthase (PHS) from Streptomyces coelicolor, and Streptomyces glaucasence; (ii) elucidating the mechanism of cryptification, and activation, of the gene(s); (iii) isolating the entire cluster of genes for the putative pathway; and (iv) exploring, through molecular intervention, the potential role of these silent alleles in the production of actinomycin or other antineoplastic agents. It is anticipated that the proposed experiments will yield a significant amount of information which will be useful in continued examination of members of this bacterial genus for silent pathways for the synthesis of novel antibiotics. This project will also provide a much-needed opportunity for the training of undergraduate students at the applicant institution, in the area of molecular biology and microbial genetics.