"This project aims at producing a fully functional light energy conversion system that is inspired by, but does not necessarily mimic, the fundamental solar energy conversion unit of natural photosynthesis – the photosystem. This is a formidable challenge that can be met with thorough understanding of biological energy and electron transfer processes, and the growing capabilities of computational protein design. Here, this knowledge and capabilities will be further developed and utilized for the design and construction of multi-cofactor, multi-subunit protein complexes with photosystem functionality. These will be designed to efficiently capture light in the visible and near infrared range, exploit it for driving the oxidation of a molecular redox carrier at one end, and providing highly reducing electrons at the other end.Our general goal will be achieved by designing protein-cofactor complexes that will facilitate light-driven electron- and excitation energy-transfer that will make up the reaction center, and light harvesting modules, respectively. Constructing protein scaffolds that will assemble and organize arrays of multiple pigments, and chains of redox cofactors are significant challenges at the forefront of the field of protein de novo design, and current theories of biological energy and electron transfer.Success will set a new standard, well beyond the current state of the art, for our ability to use computational protein design methods for assembling functional protein-cofactor complexes. These can be used as benchmarks to test and validate the engineering principles of biological energy conversion systems, as well as new ideas about their evolution. Practically, it will open new and exciting technological possibilities for constructing artificial solar energy conversion systems from biological building blocks, which may enable their introduction into living systems and the construction of novel bioreactors for light driven fuel production."