The functional organisation of a developing light harvesting system

地球上几乎所有的生命都从植物或它们的单细胞水生藻类中获得生长所需的食物和氧气。然而，更简单的细菌光合生物生活在海洋、湖泊和池塘中，对全球食物链做出了重大贡献。这些细菌是理想的研究对象，因为它们易于生长和研究，如果我们要了解蛋白质（微小的生物机器）的组成，这是一个必不可少的特征，这些蛋白质可以捕获光，然后将其转化为可以用来为活细胞提供动力的化学能。我们的工作研究了一种特殊类型的蛋白质，一种光收集复合体（LHC），它可以捕获光，并沿着相同的LHC网络将其传递给一种特殊的蛋白质，即反应中心（RC）。RC蛋白以质子梯度的形式将光能转化为化学能——类似于给生物电池充电。为了发挥其功能，这些蛋白质必须在细胞内形成有序的网络，但我们不知道这是如何实现的。我们将使用一种被称为原子力显微镜的成像技术，从字面上“感受”LHC和RC蛋白质的形状，因为细胞将它们组成网络。通过这种方式，我们将遵循导致细胞内部功能网络的事件顺序，从而解开大自然如何实现生物工程壮举的秘密。

Nearly all life on Earth gets the food and oxygen it needs to grow from plants or their single celled equivalents the aquatic algae. However, simpler, bacterial photosynthetic organisms live in oceans, lakes and ponds and make a significant contribution to the global food chains. These bacteria are ideal for research as they are easy to grow and study, an essential feature if we are to understand the make up of the proteins ( the tiny biological machines ) that capture light and then convert this into chemical energy that can be used to power the living cell. Our work examines a particular type of protein, a light-harvesting complex (LHC), that can capture light and pass it along a network of identical LHCs to a specialised protein, the reaction centre (RC). The RC protein converts the light energy to chemical energy in the form of a proton gradient - akin to charging up a biological battery. In order to perform their function these proteins must form ordered networks within the cells, but we do not know how this is achieved. We will use a form of imaging known as an atomic force microscope to literally 'feel' the shapes of the LHC and RC proteins as the cell makes networks of them. In this way we will follow the sequence of events that leads to the functional network inside the cells and thus unlock the secret of how nature achieves this feat of bio-engineering.