PSII-LHCII Supercomplex Organizations in Photosynthetic Membrane by Coarse-Grained Simulation

Green plant Photosystem II (PSII) and light-harvesting complex II (LHCLI) in the stacked grana regions of thylakoid membranes can self-organize into various PSII LHCII supercomplexes With crystalline Of fluid-like supramolecular structures to adjust themselves with external stimuli suth as high/low light and 'temperatures, reuclering tunable solar light absorption spectrum and photosynthesis efficiencies. However, the mechanisms controlling the PSII LHCH Supercomplex organizations remain elusive: In this work, We constructed a coarse-grained (CO) model of the thylakoid membrane including lipid molecules and a PSII LHCII supercomplex considering association/dissociation of moderately bound-LHCHs. The CG interaction between CG beads were constructed based on electron microscope (EM) experimental results, and we were able to Simulate the PSII LHCII supramolecular organization of a 500 X 500 nm(2) thylakoid membrane, which is compatible with experiments. Our CGMD simulations can successfully reproduce order structures of PSII LHCII supercomplexes under various protein packing fractions, free-LHCII:PSII ratios, and temperatures, thereby providing insights into mechanisms leading to PSH LHCII stipercornplex organizations in photosynthetic membranes.