부산대학교 도서관

The three dimensional structure of the photosynthetic reaction center from Rhodobacter (Rb.) sphaeroides has been determined using x-ray diffraction technique. It has 11 membrane spanning helixes, five each from the L and M subunit and one from the H subunit. There is a pseudo-twofold symmetry between the L and M subunits and their amino acid sequences have some similarity. The pigment components, which are located at the hydrophobic core of the reaction center also have this symmetry. We confirmed that two bacteriochlorophylls have a predicted conformation called a special pair.'' The nonheme iron is liganded with four histidines and one glutamic acid. 13 refs., 2 figs.