Photosynthesis is a crucial process that allows plants to convert carbon dioxide into organic compounds using solar energy. Light-harvesting complex II (LHCII) is a complex of pigment molecules bound to proteins. It switches between two main functions—dissipating harmful excess light energy as heat under high light intensity through nonphotochemical quenching, and transferring absorbed light to the reaction center with almost a unit efficiency under low light.
Bioengineering studies have shown that accelerating the transition between these two functions can increase photosynthetic efficiency—for example, soybean yields have been reported to increase by up to 33%. However, the atomic-level dynamic structural changes in LHCII that activate such allosteric regulation had not been previously elucidated.
ln this study, researchers led by Prof. Weng Yuxiang from the Institute of Physics of the Chinese Academy of Sciences, together with Prof. Gao Jiali’s group from Shenzhen Bay Laboratory, combined single-particle cryo-electron microscopy (cryo-EM) studies of dynamic structures of LHCII at atomic resolution with multistate density functional theory (MSDFT) calculations of energy transfer between photosynthetic pigment molecules to identify the photosynthetic