Univ. of Illinois at Urbana-Champaign. The PSU constitutes a highly efficient machinery for absorbing and utilizing absorbed light quanta. Photons are absorbed by LHs and transferred in the form of electronic excitation towards the photosynthetic reaction center for photoinduced charge separation. The impact of this research will likely go beyond an understanding of bacterial light harvesting. Once the physical principles governing the light harvesting and electron transfer processes in the photosynthetic organisms, selected and optimized in billions of years of evolution, are understood, we may apply the same principles to engineer solar cells.
Membrane proteins are vital to many cellular and physiological processes.
Knowledge of three dimensional structures of membrane proteins is urgently needed for understanding of their biological functions. To resolve a structure from measured diffraction intensities requires knowledge of phases which is unobtainable from a single diffraction experiment. Conventionally, the phase problem is solved by means of the multiple isomorphous replacement method, which requires two or more isomorphous heavy metal derivatives. An alternative solution to the phase problem is to phase the structure by using a homologous structure in a procedure called molecular replacement. In this method, a homologous probe structure is fit into the unit cell of the unknown structure and used to generate an initial phasing model for the unknown structure.