Structure of the Tat protein translocase

所有的细菌都会产生在细菌细胞外运作的蛋白质。细菌病原体产生的毒素就是很好的例子。由于细菌只在细胞内制造蛋白质，新合成的细胞外蛋白质必须穿过正常不透水的细胞膜移出细胞。这项任务是由位于细胞膜上的名为蛋白质转运体的机器执行的。TAT蛋白转运体存在于许多不同的细菌中，包括几乎所有导致人类疾病的细菌，如结核分枝杆菌(导致结核病)和沙门氏菌(导致食物中毒)。在致病细菌中，TAT转运蛋白是细菌致病所必需的。因此，科学家们对开发阻止TAT系统工作的药物越来越感兴趣。为了了解TAT机械是如何工作的，并最终设计出阻止它工作的新药，该项目旨在利用X射线结晶学来确定TAT运输装置的结构。

All bacteria produce proteins that operate on the outside of the bacterial cell. Good examples of this are the toxins produced by bacterial pathogens. Since bacteria only make proteins inside the cell, the newly-synthesised extracellular proteins must be moved out of the cell across the normally impermeable cell membrane. This task is carried out by machines termed protein transporters that are located in the cell membrane. The Tat protein transporter is found in many different bacteria including almost all those which cause human diseases such as Mycobacterium tuberculosis (which causes tuberculosis), and Salmonella (which causes food poisoning). In pathogenic bacteria the Tat transporter is essential for the bacterium to cause disease. Thus, scientists are becoming increasingly interested in developing drugs that prevent the Tat system from working. In order to understand how the Tat machinery works, and ultimately to design new drugs to stop it working, this project aims to determine the structure of the Tat transport apparatus using X-ray crystallography.