Chlorosome

[2] They differ from other antenna complexes by their large size and lack of protein matrix supporting the photosynthetic pigments.

Green sulfur bacteria are a group of organisms that generally live in extremely low-light environments, such as at depths of 100 metres in the Black Sea.

[8] Because they have been so difficult to study, the chlorosomes in green sulfur bacteria are the last class of light-harvesting complexes to be characterized structurally by scientists.

Each individual chlorosome has a unique organization and this variability in composition had prevented scientists from using X-ray crystallography to characterize the internal structure.

With distance constraints and DFT ring current analyses, the organization was found to consist of unique syn-anti monomer stacking.

The combination of NMR, cryo-electron microscopy and modeling enabled the scientists to determine that the chlorophyll molecules in green sulfur bacteria are arranged in helices.

The interactions that lead to the assembly of the chlorophylls in chlorosomes are rather simple and the results may one day be used to build artificial photosynthetic systems that convert solar energy to electricity or biofuel.