The Assembly of Tetrathionate Reductase in Pathogenic Bacteria

细菌是人类已知的最简单、最真实的生物。一些细菌是危险的，沙门氏菌是发达国家食源性疾病的主要原因之一。许多细菌可以在没有氧气的情况下生存和生长，而是利用环境中的其他化学物质来产生生命所需的能量。沙门氏菌就是这样一种细菌，它用令人印象深刻的酶武装装饰自己的表面，用这些酶来给自己充电。构建这些酶对细胞来说是一个复杂的过程，涉及到金属、原子和其他蛋白质的招募，以形成最终的成品酶。如果科学家故意干预这一过程，新的突变体？被分离出来的细菌被发现不再有危险。事实上，这些酶中的许多经常在细胞表面的外面被发现，这是一个关键的兴趣。这些酶是如何走出细胞的，以及它们是如何与之前连接的所有金属和亚基完全组装在一起的，这是这项研究项目的重点。大多数注定位于细胞外的酶都可以通过存在特殊的？信号？来识别。在他们身上。我们发现，这种同样由蛋白质组成的信号在细胞中有两种功能。首先，它有助于组装亚基和金属，其次，它有助于将完成的酶定位在细胞外。为了做到这一点，信号与一名监护人协同工作。与之广泛相互作用并调节其功能的蛋白质。一旦我们详细了解了这些过程是如何工作的，我们就可能了解到如何设计一种新的抗生素来阻止这一系统在不损害环境的情况下在沙门氏菌中发挥作用。这些类型的过程不被人类细胞使用，这使得它们成为开发新型抗菌药物的一个非常有吸引力的目标。

Bacteria are the simplest truly living things known to man. Some bacteria are dangerous and Salmonella is one of the primary causes of foodborne illness in the developed world. Many bacteria can live and grow without oxygen, and instead utilise other chemicals from the environment to generate energy for life. Salmonella is one such bacterium and it decorates the surface of itself with an impressive armoury of enzymes, which it uses to energize itself. Building these enzymes is a complicated process for the cell and involves the recruitment of metals atoms and other proteins to form the final finished enzyme. If scientists interfere deliberately in this process the new ?mutant? bacteria that are isolated are found to be no longer dangerous. The fact that many of these enzymes are often found outside on the surface of the cell is of key interest. How these enzymes get out the cell, and how they are fully assembled with all their metals and subunits attached before that, is the thrust of this research project. Most enzymes that are destined to be located outside the cell are identifiable by the presence of a special ?signal? on them. We have found this signal, which is also made of protein, has two jobs in the cell. First, it helps to assemble the subunits and metals, then second, it helps to locate the finished enzyme outside the cell. To do this the signal works in tandem with a ?chaperone? protein that interacts extensively with it and regulates its function. Once we learn in detail how these processes work we may be able to learn how design a new antibiotic to stop this system working in Salmonella without harming the environment. These types of processes are not used by human cells, which makes them a very attractive target for developing novel anti-bacterials.