Understanding and exploiting general transcription factors in the antibiotic-producing Streptomyces

了解和利用产生抗生素的链霉菌中的一般转录因子

• 批准号: BB/P010385/1
• 负责人: Mark Paget
• 金额: $ 51.3万
• 依托单位: University of Sussex
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FP010385%2F1
• 关键词: Understanding; exploiting; general; transcription; factors

Most of our antibiotics derive from the Actinobacteria, a phylum of Gram positive bacteria that inhabit diverse terrestrial and aquatic habitats and includes the Streptomyces genus that produce, for example, chloramphenicol, neomycin and erythromycin. While the use of antibiotics in the second half of the 20th century transformed human health care, antimicrobial resistance in pathogenic bacteria has steadily increased and now presents itself as a major global threat to health and society. Researchers are therefore hunting for new antibiotics to replace those that are becoming obsolete and the Actinobacteria are being revisited as a major source. One reason is because recent analysis of genome sequences is revealing genes that might direct antibiotic production, but are not switched on under laboratory conditions. Scientists are therefore very interested in finding new ways to switch on such cryptic biosynthetic genes so that the products can be assayed. One approach is to generate mutations that affect the structure and function of RNA polymerase - the enzyme that transcribes (reads) DNA to generate an RNA copy that can then be translated into the respective protein. Certain mutations are thought to redistribute the RNA polymerase away genes involved in growth towards those involved in secondary metabolism including antibiotic production. These mutations might mimic the behavior of this enzyme when the bacteria run out of nutrients - the so called stringent response that ensures that RNA polymerase switches from transcribing genes involved in growth to those involved in surviving the stress. However, this process is poorly understood in Actinobacteria and recent findings have shown that RNA polymerase itself differs from well-studied model organism E. coli in containing two accessory protein factors, called RbpA and CarD, that are required for transcription. This project will investigate the stringent response and its relationship with these transcription factors. It will produce new knowledge that will help us understand the role of RbpA and CarD and generate new new ways to reactivate cryptic antibiotic biosynthetic gene clusters and engineer, using synthetic biology, new recombinant bacterial strains for the production of novel antimicrobials.

我们的大多数抗生素来自放线杆菌，这是革兰氏阳性细菌的一个门，生活在不同的陆地和水生栖息地，包括产生氯霉素、新霉素和红霉素的链霉菌属。虽然20世纪下半叶抗生素的使用改变了人类的医疗保健，但病原菌的抗菌素耐药性一直在稳步增加，目前已成为对健康和社会的重大全球威胁。因此，研究人员正在寻找新的抗生素来取代那些正在过时的抗生素，放线杆菌正被重新视为主要来源。其中一个原因是，最近对基因组序列的分析揭示了可能指导抗生素生产的基因，但在实验室条件下不会启动。因此，科学家们非常有兴趣找到新的方法来启动这种神秘的生物合成基因，以便对产品进行检测。一种方法是产生影响RNA聚合酶结构和功能的突变。RNA聚合酶是一种转录(读取)DNA的酶，产生一个RNA拷贝，然后可以翻译成相应的蛋白质。某些突变被认为会将RNA聚合酶从参与生长的基因重新分配给那些参与次级新陈代谢的基因，包括抗生素的生产。这些突变可能会模仿细菌耗尽营养时这种酶的行为--即所谓的严格反应，确保RNA聚合酶从转录与生长有关的基因切换到参与生存压力的基因。然而，放线杆菌对这一过程知之甚少，最近的发现表明，RNA聚合酶本身不同于研究得很好的模式生物大肠杆菌，因为它含有转录所需的两个辅助蛋白因子，称为RbpA和CARD。本项目将研究这种严格的反应及其与这些转录因子的关系。它将产生新的知识，帮助我们了解RbpA和CARD的作用，并产生新的方法来重新激活隐蔽的抗生素生物合成基因簇，并利用合成生物学设计新的重组细菌菌株来生产新的抗菌剂。