Computer Model Offers New Insight On Bacterial Photosynthesis

September 05, 1997

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 Chair in Physics. "The bacteria can store the energy captured from the sun better in a ring, because of the symmetry of the structure. "

To arrive at their model of the entire photosynthetic unit, Hu and Schulten used advanced computer simulation to combine their LH1 and LH2 models with the already known structure of the reaction center. The resulting computer model furnished a view of the ring-shaped chlorophyll aggregates of LH1 and LH2 and their efficient light-harvesting function.

"You can see that it is a beautifully engineered system," Hu said. "Learning how the chlorophylls are positioned and oriented in 3-D space is an important step toward understanding the functionality of this system."The research was funded by the National Institutes of Health, National Science Foundation and the private Carver Foundation.

###




University of Illinois at Urbana-Champaign

Related Bacteria Articles from Brightsurf:

Siblings can also differ from one another in bacteria
A research team from the University of Tübingen and the German Center for Infection Research (DZIF) is investigating how pathogens influence the immune response of their host with genetic variation.

How bacteria fertilize soya
Soya and clover have their very own fertiliser factories in their roots, where bacteria manufacture ammonium, which is crucial for plant growth.

Bacteria might help other bacteria to tolerate antibiotics better
A new paper by the Dynamical Systems Biology lab at UPF shows that the response by bacteria to antibiotics may depend on other species of bacteria they live with, in such a way that some bacteria may make others more tolerant to antibiotics.

Two-faced bacteria
The gut microbiome, which is a collection of numerous beneficial bacteria species, is key to our overall well-being and good health.

Microcensus in bacteria
Bacillus subtilis can determine proportions of different groups within a mixed population.

Right beneath the skin we all have the same bacteria
In the dermis skin layer, the same bacteria are found across age and gender.

Bacteria must be 'stressed out' to divide
Bacterial cell division is controlled by both enzymatic activity and mechanical forces, which work together to control its timing and location, a new study from EPFL finds.

How bees live with bacteria
More than 90 percent of all bee species are not organized in colonies, but fight their way through life alone.

The bacteria building your baby
Australian researchers have laid to rest a longstanding controversy: is the womb sterile?

Hopping bacteria
Scientists have long known that key models of bacterial movement in real-world conditions are flawed.

Read More: Bacteria News and Bacteria Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.