Bacteriochlorin-protein interactions in native B800-B850, B800 deficient and B800-Bchla(p)-reconstituted complexes from Rhodopseudomonas acidophila, strain 10050

Recently, a method which allows the selective release and removal of the 80 0 nm absorbing bacteriochlorophyll a (B800) molecules from the LH2 complex of Rhodopseudomonas acidophila strain 10050 has been described [Fraser, N.J . (1999) Ph.D, Thesis, University of Glasgow, UK], This procedure also allo ws the reconstitution of empty binding sites with the native pigment Bchla( p), esterified with phytol, We have investigated the bacteriochlorophylla-p rotein interactions in native, B800 deficient (or B850) and in B800-bacteri ochlorophylla(p)-reconstituted LH2 complexes by resonance Raman spectroscop y. We present the first direct structural evidence which shows that the rec onstituted pigments are correctly bound within their binding pockets. (C) 1 999 Federation of European Biochemical Societies.