Mechanism and function of tRNA modification and folding

蛋白质合成是维持所有生命形式的基本关键过程。此外，蛋白质合成也是生物工程的重要组成部分，特别是在活细胞外生产大量用于商业应用的蛋白质。此外，蛋白质合成缺陷会导致大量不同的疾病。在蛋白质合成过程中，遗传信息被解码并被称为转移核糖核酸或trna的关键接头分子翻译成蛋白质序列。尽管经过了50多年的研究，我们仍然不能确定所有tRNA的共同设计原则。值得注意的是，tRNA携带了许多化学修饰，但人们对tRNA修饰酶如何增强tRNA的功能和结构仍然知之甚少。我们对tRNA设计的理解上的差距阻碍了我们在蛋白质生物工程方面的能力。为了将非天然构建块整合到工程蛋白中，我们需要在蛋白质合成中高效的新型设计trna；但到目前为止，我们还无法利用化学修饰来增强trna的功能。因此，我目前的研究重点是了解天然trna的形成和功能，特别是通过修饰酶对trna进行优化。提出的研究建立在我们的突破性发现之上，即一种原型tRNA修饰酶也有助于生成正确的tRNA三维形状。本文将系统研究多种tRNA修饰酶对蛋白质合成中tRNA结构和功能的作用。具体来说，我们将研究tRNA如何被不同的酶进行化学修饰，它们如何折叠成正确的三维形状，以及tRNA修饰和折叠如何影响它们在蛋白质合成过程中的功能。通过增加我们对tRNA生物学的基础知识，我们正在为设计新型tRNA以高效生产具有新型特性的蛋白质并用于商业应用奠定基础。同时，我们的研究可以提高我们对tRNA修饰缺陷导致的遗传性疾病的认识。

Protein synthesis is a fundamentally critical process to sustain all forms of life. In addition, protein synthesis is also an important part of bioengineering, specifically the production of large quantities of proteins outside living cells for commercial applications. Also, defects in protein synthesis lead to a plethora of different diseases. During protein synthesis, the genetic information is decoded and translated into a protein sequence by critical adaptor molecules called transfer ribonucleic acids or tRNAs. Despite more than 50 years of research, we still cannot define the design principles common to all tRNA. Notably, tRNAs carry numerous chemical modifications, but it remains poorly understood how tRNA modifying enzymes enhance the functionality and structure of tRNAs. This gap in our understanding of tRNA design hampers our abilities in protein bioengineering. To incorporate non-natural building blocks in engineered proteins, we require novel, designer tRNAs that are efficient in protein synthesis; but to-date we are unable to utilize chemical modifications to enhance the functionality of tRNAs. Therefore, my current research program focuses on understanding the formation and function of natural tRNAs, specifically the optimization of tRNAs by modifying enzymes. The proposed research builds on our breakthrough discovery that a prototypic tRNA modifying enzyme also assists in generating the correct three-dimensional shape of tRNAs. Here, we will systematically study the function of multiple tRNA modifying enzymes for tRNA structure and function in protein synthesis. Specifically, we will investigate how tRNAs are chemically modified by different enzymes, how they fold into a correct three-dimensional shape, and how tRNA modification and folding affects their function during protein synthesis. By increasing our fundamental knowledge on tRNA biology, we are laying the foundation to engineer novel tRNAs for the efficient production of proteins with novel properties for commercial applications. At the same time, our research may improve our understanding of inherited diseases resulting from tRNA modification defects.