EAGER: Engineering catalytic activity into the carboxysome shell

植物在光合作用的过程中获取太阳的能量，但这是一个低效的过程，限制了它们的生长潜力。一些细菌具有特殊的结构（称为羧酸体），可以提高它们的光合作用效率，如果将羧酸体引入水稻、小麦和大豆等作物植物中，预计这将改善它们的生长和产量。重建功能性羧基体所需的蛋白质数量越少，就越容易成功。这个项目的目标是将两个羧基体蛋白的作用结合为一个；换句话说，一种蛋白质通过结合结构和酶的功能来发挥两种重要作用。有人建议开发两种类型的双功能羧基体蛋白质：一种将有助于将二氧化碳输送到羧基体内部，在那里它将被光合作用的关键酶RUBISCO所利用；第二种将解毒一种分子（2-磷酸乙醇酸），这种分子是与光合作用竞争的化学反应中不需要的副产品。更广泛的影响：该项目将为博士后和本科生提供生物化学、蛋白质化学和合成生物学的跨学科培训。此外，它还将探索诸如羧基体等结构工程的创新方法，并有可能提高粮食和生物燃料的作物产量。

Plants capture the energy of the sun in the process of photosynthesis, but this is an inefficient process that limits their growth potential. Some bacteria have specialized structures (called carboxysomes) that increase their efficiency of photosynthesis, and if carboxysomes can be introduced into crop plants such as rice, wheat and soybeans it is anticipated that this would improve their growth and yield. The smaller the number of proteins that are needed to reconstitute functional carboxysomes, the easier it will be to succeed. The goal of this project is to combine the roles of two carboxysome proteins into one; in other words, one protein will play two essential roles by combining structural and enzymatic functions. It is proposed to develop two types of bi-functional carboxysome proteins: one that will help deliver carbon dioxide to the interior of the carboxysome, where it will be available to RUBISCO, a key enzyme of photosynthesis; the second will detoxify a molecule (2-phosphoglycolate) that is formed as an unwanted by-product of chemical reactions that compete with photosynthesis.Broader Impacts: This project will provide interdisciplinary training in biochemistry, protein chemistry and synthetic biology to a postdoctoral fellow and to undergraduate students. In addition it will explore innovative approaches to the engineering of structures such as the carboxysome and has the potential to improve crop yields for both food and biofuel.