Structural diversity and modularity of photosynthetic RC−LH1 complexes

The photosynthetic reaction center−light-harvesting 1 (RC−LH1) complex is a membrane-protein core supercomplex that plays a crucial role in the primary reactions of anoxygenic photosynthesis.Recent developments of structural biology techniques have greatly promoted the structural characterization of various RC−LH1 complexes.The structural analysis provides insight into the assembly principles and functionality of RC−LH1 supercomplexes.The studies highlight the structural variations and modularity of RC−LH1 complexes among different phototrophic bacteria in an evolutionary and adaptive context.Advanced understanding of natural photosynthetic RC−LH1 structure and function could aid in the design and engineering of efficient artificial photosynthetic systems. Bacterial photosynthesis is essential for sustaining life on Earth as it aids in carbon assimilation, atmospheric composition, and ecosystem maintenance. Many bacteria utilize anoxygenic photosynthesis to convert sunlight into chemical energy while producing organic matter. The core machinery of anoxygenic photosynthesis performed by purple photosynthetic bacteria and Chloroflexales is the reaction center−light-harvesting 1 (RC−LH1) pigment–protein supercomplex. In this review, we discuss recent structural studies of RC−LH1 core complexes based on the advancement in structural biology techniques. These studies have provided fundamental insights into the assembly mechanisms, structural variations, and modularity of RC−LH1 complexes across different bacterial species, highlighting their functional adaptability. Understanding the natural architectures of RC−LH1 complexes will facilitate the design and engineering of artificial photosynthetic systems, which can enhance photosynthetic efficiency and potentially find applications in sustainable energy production and carbon capture.