CHAMPAIGN, Ill. -- Using advanced computer modeling, scientists working with photosynthetic bacteria have shed light on one of Earth's most efficient photosynthetic systems.

The accomplishment, the researchers say, should boost the understanding of light absorption and energy transfer in photosynthesis -- the process that converts solar energy into chemical energy -- and eventually lead to the development of more efficient and environmentally clean energy sources.

In the August issue of the journal Physics Today, University of Illinois scientists report their successful three-dimensional computer modeling that depicts how the two light-harvesting complexes of the purple bacteria Rhodobacter sphaeroides aggregate (combine and arrange) their chlorophyll molecules in a ring around the bacteria's photosynthetic reaction center.

Creating the modeled aggregate of light-harvesting complexes 1 and 2 (LH1 and LH2) was made possible by the research team's successful determination, reported last year, of the structure of the bacteria's LH2 from Rhodospirillum molischianum by X-ray crystallography, said Xiche Hu, a postdoctoral fellow at the U. of I. Beckman Institute for Advanced Science and Technology.

The details of last year's work, in collaboration with researchers at the Max Planck Institute for Biochemistry in Frankfurt, Germany, were published in the May 1996 issue of Structure. The method used to solve the structure involved sophisticated computational modeling. A similar LH2 structure from a different species was reported in late 1995 in the journal Nature by University of Glasgow scientists, who had determined the structure with a different method.

Because purple bacteria exist in mud, they have to use what little sunlight that is unharvested by plants quickly and efficiently for their own metabolism, said Klaus Schulten, director of the Beckman's theoretical biophysics group and holder of the U. of I. Swanlund C
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Contact: Jim Barlow, Life Sciences Editor
b-james3@uiuc.edu
217-333-5802
University of Illinois at Urbana-Champaign
5-Sep-1997