3.E.2.1.2
Reaction Center of four subunits, PufC, PufM, PufL and PuhA together with light-harvesting complex 1 of two subunits, LH1α and LH1β. The 3-D structure of the supercomplex with both RC and LH1 has been solved to 1.9 Å resolution (Kishi et al. 2020). The QB quinone binding site is converted to QBH2 upon light-induced reduction and QBH2 is transported to the quinone pool in the membrane through the LH1 ring. Quinone transport in Tch. tepidum occurs through the size-restricted hydrophobic channels in the closed LH1 ring and are consistent with structural studies that have revealed narrow hydrophobic channels in the Tch. tepidum LH1 transmembrane region (Kishi et al. 2020). The cryo-EM structure of the Rhodobacter sphaeroides RC-LH1 core monomer complex has been solved at 2.5 Å (Qian et al. 2021).