title: Reconstitution of bacterial photosynthetic unit in a lipid bilayer studied by single-molecule spectroscopy at 5 K.
abstract: As a model of photosynthetic unit (PSU), self-assembled aggregates of pigment-protein complexes from photosynthetic bacteria were prepared in a lipid bilayer by reconstitution of the light-harvesting 2 (LH2) complex and light-harvesting 1-reaction center (LH1-RC) complex through detergent removal of their micelles in the presence of lipids. By performing polarization-controlled fluorescence and fluorescence-excitation spectroscopy on single aggregates at a temperature of 5 K, the composition of individual aggregates was determined and excitation energy transfer (EET) between constituent complexes was observed. LH2 and LH1-RC from a bacterium, Rhodobacter (Rb.) sphaeroides, were found to form a trimeric aggregate in which EET takes place from one LH2 to two LH1-RCs. In contrast, a heterodimer of LH2 and LH1-RC in which EET works was found to assemble from a combination of complexes of different bacterial species, that is, LH2 from Rb. sphaeroides and LH1-RC from Rhodopseudomonas (Rps.) palustris.
authors: Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551, Japan.
authors: Daisuke
authors: D
authors: Uchiyama
authors: Hiroyuki
authors: H
authors: Oikawa
authors: Kohei
authors: K
authors: Otomo
authors: Mamoru
authors: M
authors: Nango
authors: Takehisa
authors: T
authors: Dewa
authors: Satoru
authors: S
authors: Fujiyoshi
authors: Michio
authors: M
authors: Matsushita