Pigment Composition in the Reaction Center Complex from the Thermophilic Green Sulfur Bacterium, Chlorobium tepidum: Carotenoid Glucoside Esters, Menaquinone and Chlorophylls

Distribution of pigments in the reaction center (RC) complex,chlorosomes and chlorosome-free membranes prepared from thegreen sulfur bacterium, Chlorobium tepidum, was analyzed. TheRC complex contained approximately 40 molecules of bacteriochlorophyll(BChl) a per P840, half of which are estimated to be in theFenna-Matthews-Olson (FMO) protein. Carotenes (2 molecules perP840) occupied only one third of the total carotenoids. Theremaining carotenoids (4 to 5 molecules per P840) were OH-chlorobacteneglucoside ester and OH-