Deciphering microbial metalloenzyme functions in microaerobic host environments

项目摘要 共生和致病细菌存在于人体内的各种缺氧的利基环境中，例如 胃肠道、伤口组织和肺粘膜。适应这些环境需要不同的 支持定居和生存的厌氧生物化学。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物质的基础知识 微生物在厌氧和微氧环境中使用。拟议的研究概述了我们的方法 阐明金属酶在宿主细胞中的分子机制、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核心作用。鉴于以下类别 用于氧化还原反应的活性氧的金属酶已经研究了几十年，金属酶家族 在缺乏氧气的情况下，这种功能仍然没有得到很好的描述。在这个项目中，我们审问了化学物质 以及一种新发现的在细菌中普遍存在的金属酶氧化酶家族的生物学功能 病原体和人体肠道微生物。这一家族中为数不多的已知代表催化氧不依赖 关键细胞过程中的羟化反应，包括辅因子生物合成和RNA修饰。我们会 使用这些已知的酶来建立催化的要求并辨别它们在 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是如此 代表了一种尚未开发的生化多样性来源。我们将利用基因组学和蛋白质生物信息学来 在这个特征不佳的超家族中发现新的酶化学。拟议中的工作将揭示 以前未知的氧化还原化学，建立对微氧条件的生化反应，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。这样做的最终目的是 研究计划是获得微生物对氧气限制的分子适应能力 用于治疗难以捉摸的抗药性细菌病原体。

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.