Directed Evolution of Photosystem Chemistry

光系统化学的定向进化

基本信息

批准号：
MR/T017546/1
负责人：
Tanai Cardona Londono
金额：
$ 154.68万
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=MR%2FT017546%2F1
关键词：
Directed Evolution Photosystem Chemistry

项目摘要

The importance of photosynthesis for the evolution of life can hardly be overemphasised. It represents one of the key innovations that transformed Earth and paved the way for the rise of complex life.Today, the improvement of photosynthesis to enhance crops and the production of compounds of commercial interest has become one of the grand challenges of photosynthesis research.To improve photosynthesis, it is necessary to change photosynthesis. The study of the evolution of photosynthesis is the study of how photosynthesis has changed through time, which has been the focus of my research. The study of the evolution of photosynthesis can provide relevant insight on its potential for change, optimisation, or improvement.For example, my research has shown that in several occasions through geological time, the chemistry of oxygenic photosynthesis was rapidly and radically optimised to match environments with very atypical light conditions such as those found at 200 meter-deep open ocean waters or within stromatolites. This indicated that the process has a level of plasticity and potential for adaptability well beyond what is currently recognised.I want to link my research on the evolution of photosynthesis with Directed Evolution methods to experimentally prove that it is possible to control and purposefully change the chemistry of photosynthesis.Directed Evolution is an extremely versatile method that is used to change the traits or the activity of a given enzyme by exploiting evolution. It can be done simply by subjecting an organism through repeated cycles of selection under the conditions that favour the desired traits, it can be enhanced by turbocharging mutational rates, it can be focused on a single gene of interest, and it can be combined with another method called Ancestral Sequence Reconstruction (ASR).ASR is an evolutionary method commonly used to compute the most likely ancestral state of an enzyme. The ancestral enzyme gene can then be made using commercially available services and used to study the properties of the ancestral enzyme in the test tube. An interesting outcome of ASR is that the ancestral enzymes show superior stability and functional flexibility. These properties have made the combination of ASR and Directed Evolution a powerful biotechnological tool.I currently lead a research programme on the molecular evolution of photosynthesis and this employs ASR to reconstruct the ancestral states of Photosystem II.Photosystems are nature's solar cells and they power life on Earth by converting light into useful chemical energy. They have done so for billions of years. Photosystem II uses light to decompose water into oxygen, protons, and to generate an electric current. This is the hallmark chemical reaction of oxygenic photosynthesis.The photosystems are very complex molecular machines. This complexity means that they evolve very slowly. It is often believed that they exist as "frozen metabolic accidents". A concept that was introduced to imply that these systems have reached a maximum level of optimal performance and therefore have limited evolvability: in other words, it is thought that they cannot be changed in any way that is useful. This view is however contradicted by my own work, which instead suggests the photosystems have tremendous natural adaptability potential.My research group aims to demonstrate that the function of the photosystems can be changed and controlled in any desirable way with the use of Directed Evolution. We will demonstrate that the function of the photosystems can be optimised to any particular condition given an appropriate set of selective pressures. We will provide tools and a molecular blueprint for the control and optimisation of photosystem chemistry for potential future molecular applications.

光合作用对生命进化的重要性几乎不能过分强调。它代表了改变地球并为复杂生命的兴起铺平道路的关键创新。纪念日的改善以增强农作物的光合作用和商业兴趣的化合物的产生已成为光合作用研究的巨大挑战之一。要改善光合作用，需要改变光合作用的光合作用。光合作用演变的研究是对光合作用如何随着时间而变化的研究，这一直是我研究的重点。对光合作用的演变的研究可以提供有关其变化，优化或改进的潜力的相关见解。例如，我的研究表明，在多次通过地质时代，有氧光合作用的化学迅速且从根本上优化，以匹配环境，以匹配非常非典型的光线条件，例如在200米高的Open OpenApen OpenApen Opear Opear Opear Opear Opear Opecon Pasterites或内部层面上发现的环境。这表明该过程具有远远超出当前所认识到的可适应能力的一定程度。我想将光合作用演变的研究与有方向的进化方法联系起来，以实验证明可以控制并有目的地改变光合作用的化学性能。指导的进化方法是一种极具用途的方法，可以通过启动来改变特征或启动的特征，以改变特性或范围的活动。它可以简单地通过在有利于所需特征的条件下的反复选择循环中对生物体进行进行，可以通过涡轮增压突变速率来增强，它可以集中在单个利息基因上，并且可以与另一种称为祖传序列重建（ASR）的方法结合在一起。ASR是一种进化方法，是一种常见的祖先，是一种可能符合祖先的进化方法。然后可以使用市售服务制成祖先酶基因，并用于研究试管中祖先酶的性质。 ASR的一个有趣结果是，祖先酶显示出优越的稳定性和功能灵活性。这些特性使ASR和定向进化的结合成为了强大的生物技术工具。我目前领导了一项有关光合作用分子演化的研究计划，并采用ASR来重建光系统II的祖先状态II.Photosystems是自然的太阳能细胞，它们通过将光线推动到有用的化学化学能源上。他们这样做了数十亿年。 Photosystem II使用光将水分解为氧气，质子，并产生电流。这是氧化光合作用的标志性化学反应。光系统是非常复杂的分子机器。这种复杂性意味着它们的发展非常缓慢。人们通常认为它们是“冷冻代谢事故”。引入的概念暗示这些系统已经达到了最佳的最佳性能水平，因此具有有限的发展性：换句话说，人们认为它们不能以任何有用的方式进行更改。但是，这种观点与我自己的作品相抵触，这表明光系统具有巨大的自然适应性潜力。我的研究小组的目标是证明光系统的功能可以通过使用定向进化来以任何理想的方式更改和控制。我们将证明，在给定适当的选择压力的情况下，可以将光系统的功能优化到任何特定条件。我们将提供工具和分子蓝图，以控制和优化光系统化学，以实现潜在的未来分子应用。