Investigations of lanthipeptides derived from human gut microbiome

项目摘要/摘要 抗生素耐药性的出现构成了严重的全球威胁，人类、动物日益关注 和环境健康。因此，迫切需要寻找新抗生素的替代来源。 在抗击病原体感染的同时限制细菌耐药性的出现。范德东克集团 重点研究一类核糖体合成和翻译后修饰的兰硫肽 多肽(RIPP)：以羊毛硫氨酸和甲基羊毛硫氨酸环为特征的天然产物，具有潜在的 新型药物和抗菌剂。事实上，兰硫肽Nisin已经被美国利用。 食品工业作为防腐剂对抗食源性病原体已有50多年的历史，但几乎没有 细菌耐药性的发展。人类微生物组是新的RIPP样次生体的丰富来源 具有强效抗菌性能的代谢物。然而，几乎所有这些天然产品的身份都是 未知，它们的生物学作用也鲜为人知。因此，更深层次地分析人类微生物群衍生 天然产物不仅将导致新的抗菌化合物的发现，而且还将引导新的 寻求调节人类微生物区系以影响人类健康的疗法。通过基因组挖掘， 从乳杆菌C6A11(Lah)中分离出三个新的梭状芽胞杆菌Ripp生物合成基因簇(BGC)， 和梭状芽胞杆菌属(Clostridium)鉴定出AF15-17lb(CLS)。沙棘科细菌C6A11 定植于人类肠道和其他沙棘螺科细菌与2型糖尿病有关，并对 艰难梭菌肠道定植--院内抗生素相关性腹泻的主要原因。英国广播公司 是独一无二的，因为它们编码了一个耐人寻味的翻译后修饰酶(PTM)星座 与几种不同的前体多肽相结合，天然产物就是从这些多肽中衍生出来的。然而， 所有这些天然产物的身份尚不清楚，其生物合成也鲜为人知。因此， 本文提出的研究旨在通过首先开发一种新的普遍适用的 用于获取来自大肠杆菌和/或产孢子杆菌的这些天然产物以进行表征的平台 生物活性筛选。此外，还将通过系统基因来检测每种ptm酶的作用。 删除。PTM酶的结构-功能关系将通过蛋白质结晶学进行检测。 其中一个子集将进行生物工程，以实现新的功能。完成拟议的研究将导致 发现多达11种具有潜在治疗应用/干预作用的新型RIPP天然产品 以及开发一个新的普遍适用的平台，用于从 人类肠道微生物群。此外，这项研究的发现将提供一个工具、知识的平台 以及将延伸到未来新抗生素发现的技术，并将形成预测 从人类肠道微生物群中鉴定其他类似复杂的BGC。

Project Summary/Abstract The emergence of antibiotic resistance poses a serious global threat of growing concern to human, animal and environmental health. Therefore, there is an urgent need to discover alternative sources of new antibiotics to combat pathogenic infections while limiting the emergence of bacterial resistance. The van der Donk group focuses on the study of lanthipeptides, a class of ribosomally synthesized and posttranslationally modified peptide (RiPP) natural products characterized by lanthionine and methyllanthionine rings that have potential as novel pharmaceuticals and antimicrobial agents. Indeed, the lanthipeptide nisin has been utilized by the U.S. food industry as a preservative to combat food-borne pathogens for more than 50 years with little to no development of bacterial resistance. The human microbiome is a rich source of novel RiPP-like secondary metabolites with potent antimicrobial properties. However, the identities of nearly all these natural products are unknown, and their biological roles are poorly understood. Thus, a deeper analysis of human microbiome-derived natural products would not only lead to the discovery of new antimicrobial compounds but also guide new therapies that seek to modulate the human microbiota in order to impact human health. Through genome mining, three novel Clostridiales RiPP biosynthetic gene clusters (BGC) from Lachnospiraceae bacterium C6A11 (lah), Clostridium indicum (cli) and Clostridium sp. AF15-17LB (cls) were identified. Lachnospiraceae bacterium C6A11 colonizes the human gut and other Lachnospiraceae bacterium are linked to type 2 diabetes, and resistance to gut colonization by Clostridium difficile - a leading cause of nosocomial antibiotic-associated diarrhea. The BGCs are unique in that they encode an intriguing constellation of posttranslational modification enzymes (PTM) in conjunction with several distinct precursor peptides from which the natural products are derived. However, the identities of all these natural products are unknown and their biosynthesis poorly understood. Therefore, the research proposed herein is designed to examine all three BGCs by first developing a new generally applicable platform for accessing these natural products from E. coli and/or C. sporogenes for characterization and bioactivity screening. In addition, the role of each PTM enzyme will be examined through systematic gene deletions. The structure-function relationships of the PTM enzymes will be examined via protein crystallography and a subset will be bioengineered towards new functionalities. Completion of the proposed research will lead to the discovery of up to eleven novel RiPP natural products with potential therapeutic applications/interventions and the development of a new generally applicable platform for accessing other RiPP-like natural products from the human gut microbiome. In addition, the findings from this research will provide a platform of tools, knowledge and techniques that will extend to future discovery of new antibiotics and will form a blueprint for predicting the identity other similarly complicated BGCs from the human gut microbiome.