Deciphering microbial metalloenzyme functions in microaerobic host environments

项目摘要 共生菌和致病菌栖息在人体内各种缺氧的小生境中，例如 胃肠道、伤口组织和肺粘膜。适应这些环境需要不同的 厌氧生物化学，以支持殖民和生存。对这些生化策略的理解 可能为开发克服抗生素挑战的新疗法提供独特的机会 耐药性和细菌持久性。然而，我们缺乏对各种化学的基本知识， 微生物在厌氧和微需氧环境中使用。拟议的研究概述了我们的方法， 阐明金属酶在宿主中的分子机制、生化反应和生物学作用， 微生物相互作用金属酶在细胞氧化还原化学中起着重要作用。而类 金属酶，活性氧的氧化还原反应已经研究了几十年，金属酶家族 在没有氧气的情况下的功能仍然很难表征。在这个项目中，我们审问化学物质 和生物学功能的一个新发现的家庭的金属酶氧化酶，普遍存在于细菌 病原体和人体肠道微生物。这个家族的少数已知代表催化不依赖于氧的 在关键细胞过程中的羟基化反应，包括辅因子生物合成和RNA修饰。我们将 使用这些已知的酶来建立催化的要求，并辨别它们在以下方面的假定作用： 微氧条件除了具有既定功能的成员外，新兴的金属酶家族也 代表着尚未开发的生物多样性资源。我们将利用基因组学和蛋白质生物信息学， 在这个特征不明显的超家族中发现新的酶化学。拟议的工作将揭示 以前未知的氧化还原化学，建立微需氧条件下的生化反应，并设置 阶段询问这些反应在宿主-微生物相互作用中的重要性。这个项目的最终目标 研究计划是获得微生物适应O2限制的分子理解，可以 用来治疗难以找到的耐药病原体

Project Summary Commensal and pathogenic bacteria inhabit various oxygen-depleted niches in the human body, such as the gastrointestinal tract, wound tissue, and the lung mucosa. Adaptation to these environments requires distinct anaerobic biochemistry to support colonization and survival. An understanding of these biochemical strategies could present unique opportunities to develop novel therapeutics that overcome challenges of antibiotic resistance and bacterial persistence. However, we lack fundamental knowledge of the diverse chemistry that microbes use in anaerobic and microaerobic environments. The proposed studies outline our approach to elucidate the molecular mechanisms, biochemical reactions, and biological roles of metalloenzymes in host- microbe interactions. Metalloenzymes play central roles in cellular redox chemistry. Whereas classes of metalloenzymes that active oxygen for redox reactions have been studied for decades, metalloenzyme families that function in the absence of oxygen remain poorly characterized. In this project, we interrogate the chemical and biological functions of a newly discovered family of metalloenzyme oxidases that are prevalent in bacterial pathogens and human gut microbes. The few known representatives of this family catalyze oxygen-independent hydroxylation reactions in key cellular processes, including cofactor biosynthesis and RNA modification. We will use these known enzymes to establish the requirements for catalysis and to discern their postulated roles in microoxic conditions. Beyond the members with established functions, emerging metalloenzyme families also represent an untapped source of biochemical diversity. We will leverage genomics and protein bioinformatics to discover new enzymatic chemistry within this poorly characterized superfamily. The proposed work will reveal previously unknown redox chemistry, establish biochemical responses to microaerobic conditions, and set the stage to interrogate the importance of these reactions in host-microbe interactions. The ultimate goal of this research program is to gain a molecular understanding of microbial adaptation to O2 limitation that can be leveraged to treat elusive drug-resistant bacterial pathogens.